Fred C. Adams, University of Michigan PLANET MIGRATION: The effects of Disk Torques, Planet-Planet Scattering, and Turbulent Fluctuations Abstract: This talk describes theoretical studies of planet migration in star/disk systems. These dynamical systems are highly chaotic, so that multiple realizations of the calculations must be performed and the results must be presented in terms of the distributions of possible orbital elements. During the planet formation epoch, both residual circumstellar disks and multiple planets are expected to be present. Disk torques and planet-planet scattering change the orbital elements of migrating planets in complementary ways. Disks are effective at moving planets inward (changing the semi-major axes), whereas planet-planet scattering is effective at increasing the orbital eccentricities. The interplay between these two effects leads to a wide variety of possible outcomes. This model of migration -- driven by tidal interactions with a disk and by dynamical scattering from other planets -- naturally produces the observed range of semi-major axis and eccentricity. Next, we show how type I migration is affected by turbulent density fluctuations in the disk. For type I migration, the planet does not clear a gap in the disk and its secular motion is driven by torques generated by the wakes it creates in the surrounding disk fluid. MHD turbulence creates additional density perturbations that gravitationally interact with the planet and can dominate the torques produced by the migration mechanism itself. Conventional type I migration can be readily overwhelmed by turbulent perturbations and hence the usual description of type I migration must be modified wherever the magnetorotational instability is active. The migrating planet does not follow a smooth inward trend, but rather exhibits a random walk through phase space. MHD turbulence thus alters the time scales for type I planet migration and the time scales display a full distribution of values. _____________________________________________________________________ Suzanne Aigrain (1), Simon Hodgkin (1), Jonathan Irwin(1), Mike Irwin (1) (1) IoA, Cambridge, UK Searching for planetary transits and rotation periods in the Orion Nebula Cluster We have recently started monitoring the Orion Nebula Cluster (ONC) using the Wide Field Camera (WFC) on the 2.5m Isaac Newton Telescope (INT) on La Palma. The primary aim of this survey is to search for transits by close-in giant exo-planets orbiting very young stars (ONC age: 1-3 Myr). Detecting such planets would provide very important constraints for planet formation and early evolution scenarios. Additional science goals include searching for low-mass eclipsing binaries and measuring rotation periods for hundreds of low- and very low-mass stars. The intrinsic variability of young low mass stars, which exhibit both aperiodic and periodic variations at the 10% level on timescales of a few days and less, makes the detection of planetary transits in the ONC even more challenging than it is around older stars. We will discuss techniques to characterise this variability and to disentangle it from potential transit signals. Preliminary results from our first two observing runs will be presented. Finally, we will discuss potential applications of these techniques to other ground- and space based transit searches. Suzanne Aigrain (1), Mike Irwin (1), Gerry Gilmore (1), Fabio Favata (2), Claire Moutou (3) and the CoRoT Exo-planet Working Group (1) IoA, Cambridge, UK (2) ESA/ESTEC, Noordwijk, The Netherlands (3) OAMP, Marseille, France Prospects for detecting Hot Earths with COROT CoRoT (Convection, Rotation and Transits) is a small CNES/ESA mission with a launch date of June 2006. It will carry out high precision, high time sampling photometry of 10,000s of stars for periods up to 5 months. Its two primary science goals are to detect exo-planets via the transit method down to terrestrial masses, and to perform asteroseismology of stars across the HR diagram. Recently, the CoRoT Exo-planet Working Group carried out a blind transit detection exercise, which aimed to test several light curve detrending and transit search methods and compare their effectiveness on realsitic simulated CoRoT light curves. I will discuss the results of this exercise and the limits for planet detectability with CoRoT that can be inferred from it, particularly in the close-in (a < 0.1 AU), terrestrial (R_p < 2.2 R_Earth) regime. _____________________________________________________________________ Jeremy Bailey, Australian Centre for Astrobiology, Macquarie University, Sydney, Australia Planet Detection from Dome C in Antarctica Dome C (Concordia Station) lies at an altitude of 3250m on the Antarctic Plateau. The cold, dry, stable air at this location makes it an outstanding location for astronomical observation. The site offers particular advantages for a number of planet detection techniques. As a photometric site it provides low scinitillation, stable transparency and the possibility of continuous 24 hour coverage, making it the ideal place for transit detection and follow-up studies. The excellent seeing and low winds make it also an ideal site for the construction of an extremely large telescope for direct imaging of extrasolar planets. ____________________________________________________________________ John Bally Department of Astrophysical and Planetary Sciences Center for Astrophysics and Space Astronomy Center for Astrobiology University of Colorado, Boulder Planet Formation in OB Associations The majority (~90%) of all stars in the sky form in dense clusters containing from tens to many thousands of stars. Most of these clusters are transient gravitationally unbound entities which expand and dissolve on a time-scale of several million years, comparable to the time required for planet formation. In these environments, intense UV radiation, powerful stellar winds, and supernova explosions effect protoplanetary disk evolution. There is emerging evidence that our Solar system formed in just such an environment. Contrary to previous ideas, recent work suggests that OB associations and HII regions may be ideal sites for planetary system birth. The inner parts of disks (to radii of tens of AU from the central star) can survive photo-erosion for many millions of years, longer than the survival time of unbound clusters and their most massive stars. Furthermore, the photo-erosion of light gases increases the concentration of heavy elements, rocks, and ices, possibly to the point of gravitational instability. Thus, UV radiation may facilitate planetesimal formation. Supernovae in OB associations can supply the short-lived nuclei such as 60Fe and 26Al known to be injected into our Solar System within a few million years of its birth. I will present new ACS observations of young disks in the Orion Nebula, the nearest actively forming OB association, and review some of the consequences of planet formation in Orion-like environments. _____________________________________________________________________ Gaspar Bakos (Harvard CfA) Exoplanet search with the HAT Network We give an overview of the current status of the HATNet, a system consisting of six fully automated, wide (8x8 deg) field, fast-focal ratio telescopes, aiming for the discovery of transiting planets around bright stars. A secondary goal is to monitor selected areas of the sky for variability. HATnet utilizes two sites that are separated in longitude: the Fred Lawrence Whipple Observatory (FLWO) in Arizona with four, and the Submillimeter Array (SMA) site atop Mauna Kea, Hawaii with two HAT telescopes, respectively. HATNet has been built up gradually since the Spring of 2003, and currently all six units are operational. The telescopes are connected to each other via the Internet in an automated way, and field observations are performed by the two sites in an optimal way to ensure maximum coverage of the light-curves. In the past 1.5 years we have accumulated some 77,000 science frames at 5 minute time resolution on 15 selected fields. We processed the 1.5Tb data, and derived light-curves for 100,000 stars, with 25,000 reaching precision better than 1%. The data was searched for transits by the BLS algorithm, and 120 potential transit candidates were found. These were in turn followed up by "rejection mode spectroscopy" using the CfA Digital Speedometers at Oak Ridge Observatory and FLWO, or by follow-up photometry, using the 48" telescope at FLWO, and almost all of them turned out to be stellar systems that mimic planetary transits. We describe our methodology of searching for transits, and give examples of the false positives. _____________________________________________________________________ Pierre Barge (OAMP, France) Dust-gas coupling in protoplanetary disks: back reaction of the particles onto the gas Using a 2D-2phase hyrdodynamical code, developed for the study of protoplanetary disks (Inaba and Barge, A&A 2004), we study a number of situations in which the solid particles of the equatorial layer can drive a significant back reaction of the gas slowing down drift motions. Pierre Barge A new algorithm to detect planetary transits We present a new method for signal denoising and transit detection in stellar photometric light-curves. The plane light-curve can be considered as a 2D image which splits into the upper and the lower part of the plot itself. The resulting images are analysed with an image processing method enabling to develop new algorithm for filtering and detection. These algorithms have been adapted in the case the data issued from the OGLE survey. _____________________________________________________________________ Rory Barnes (U Washington) Packed Planetary Systems I: Evidence Through numerical simulations evidence for the packed nature of planetary systems is presented. Most known systems lie near instability in the sense that slight changes (sometimes less than 10%) in one orbital element can result in an ejection in less than 10^5 orbits. Some systems lie further from instability, but they cannot support an asteroid belt in between the extant planets, let alone an additional planet. The solar system is also shown to be packed. Whether this phenomenon is ubiquitous among planetary systems, or just a function of a small number of observations remains to be seen, but it may provide constraints on planet formation models, and suggest locations to search for additional planets. _____________________________________________________________________ Joseph Barranco (UCSB) Planet Embryos in Vortex Wombs We present the results of high-resolution, three-dimensional (3D) hydrodynamic simulations of the dynamics and formation of coherent, long-lived vortices in stably-stratified protoplanetary disks. Tall, columnar vortices that extend vertically through many scale heights in the disk are unstable to small perturbations; such vortices cannot maintain vertical alignment over more than a couple scale heights and are ripped apart by the Keplerian shear. Short, finite-height vortices that extend only one scale height above and below the midplane are also unstable, but for a different reason: we have isolated an antisymmetric (with respect to the midplane) eigenmode that grows with an $e$-folding time of only a few orbital periods; the nonlinear evolution of this instability leads to the destruction of the vortex. Serendipitously, we observe the formation of 3D vortices that are centered not in the midplane, but at one to three scale heights above and below. Breaking internal gravity waves create vorticity; anticyclonic regions of vorticity roll-up and coalesce into new vortices, whereas cyclonic regions shear into thin azimuthal bands. Unlike the midplane-centered vortices that were placed \textit{ad hoc} in the disk and turned out to be linearly unstable, the off-midplane vortices form naturally out of perturbations in the disk, and are stable and robust for many hundreds of orbits. _____________________________________________________________________ Gibor Basri, Astronomy Dept., Univ. of California, Berkeley Habitable Planets Around Small Stars Most of the stars in the Galaxy have less than half the mass of our Sun. If habitable planets occur around them at a rate which is at all comparable to that for solar-type stars, then low-mass stars are the locus of the "average habitat" for life. This advantage is compounded by their much longer main-sequence lifetimes. NASA's Kepler Mission will conduct the first serious search for terrestrial planets in the habitable zones of solar-type and low-mass stars. The mission is designed to be able to detect "true-Earth analogs", but in fact will conduct a much broader assay of planetary and stellar types. Indeed, the very ubiquity of low-mass stars guarantees that they constitute a major part of the Kepler target list. For Kepler, the faintness of low-mass stars is balanced by the fact that planets in their habitable zones have shorter orbital periods, and the ratio of stellar to planetary area (which determines transit depth) is more favorable (for a given planetary size). M stars have an undeserved reputation as poor places to live near (tidal synchronization and stellar flares being the most cited problems). I argue that neither of these constitutes much of a barrier to habitability. _____________________________________________________________________ A.Bedalov*, R.Neuhaeuser*, E.Guenther** M.Mugrauer* * Astrophysical Institut and University Observatory - Jena, Germany ** Thuringer Landessternwarte Tautenburg, Germany DIRECT IMAGING SEARCH FOR YOUNG MASSIVE PLANETS Everyone would like to see an image of an extrasolar planet. So far, the radial velocity detection method has only detected giant planets indirectly by measuring the wobble of the planet's parent star toward or away from us. Direct imaging of extrasolar planets, then, is highly desirable because one could separate the light from the star and the planet . However, such imaging is difficult. The most important difficulty is the dynamic range of star. Our project is direct imaging detection of sub-stellar companions around young nearby stars, within 150 pc, up to 100 Myrs young. By deep IR imaging with AO (e.g. VLT-NaCo), we can detect brown dwarfs with separations down to 20 AU around the young stars. Direct imaging detection of a massive planet will probably work first around a young stars. _____________________________________________________________________ Chas Beichman, Michelson Science Center Finding Planets: From Spitzer to TPF NASA has made the detection of Earth-like planets around nearby stars a major focus of its space science program.The current program consists of a number of missions, including the Keck Interferometer, Kepler, the Space Interferometric Mission (SIM) and a coronagraphic and interferometric versions of the Terrestrial Planet Finder. I will discuss the overall program with an emphasis on the exciting near term science that will form the scientific context for these missions. Chas Beichman, G. Bryden, K. Stapelfeldt, M. Werner (JPL) G. Rieke, D. Trilling, J. Stansberry (UofA) Disks and Planets: Spitzer Results on Disks and Planets Photometry and spectroscopy with the MIPS and IRS instruments have revealed the presence of disks of material around planet-bearing stars. I will review results obtained to date and discuss the follow-up IRS results of the first disks detected by MIPS. C. Beichman, G. Bryden, K. Stapelfeldt, M. Werner, T. Gautier (JPL) G. Rieke, D. Trilling, J. Stansberry, K. Su, C. Chen, & the MIPS instrument team (UofA) Spectra of debris disks with Spitzer We've used the InfraRed Spectrograph (IRS) on the Spitzer Space Telescope to examine a sample of 45 F5-K5 main-sequence dwarf stars, looking for emission above the stellar photosphere. The three modules used cover each stellar spectra from 8 to 35 um. Observations made during the first six months of Spitzer's mission have been reduced with careful flat-fielding in order to remove residual pixel-to-pixel calibration problems down to <3%. In most cases, the lack of a detected excess rules out the presence of hot (100-1000K) dust at the level of 100-1000 times our zodiacal cloud. Around one star, a nearby K dwarf, we've found prominent dust emission indicative of small, crystalline grains that must be located within 1 AU of the star. We will discuss possible asteroidal or cometary origins for this dust. _____________________________________________________________________ Beth Biller (U Arizona) Simultaneous Differential Extrasolar Planet Imaging (SDI) at the VLT and MMT We discuss data reduction techniques and results from the Simultaneous Differential Imager (SDI) implemented at the VLT (Lenzen et al. 2004) and the MMT. SDI uses a quad filter to take images simultaneously at 3 wavelengths surrounding the 1.62 $\mu$m methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be attenuated by a factor of $>$10$^2$. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss results from a custom algorithm implemented in IDL to perform this reduction. In our commissioning runs at the VLT and MMT, we achieved contrasts up to a factor of 45000 ($\Delta$H=11.7) at a separation of 0.6" from the primary star. With this degree of attenuation, we should be able to image a 2-4 Jupiter mass planet at 5 AU around a 30 Myr star at 10 pc. We believe that our SDI images are the highest contrast astronomical images ever made from ground or space. _____________________________________________________________________ Cullen Blake (Harvard CfA) The PAIRITEL Low-mass Transit Survey Observations of small stellar and sub-stellar objects, such as late M dwarfs and early L dwarfs, have several advantages when searching for extrasolar planets by the transit method. These objects small radii result in large photometric signals, meaning that companions as small as Earth could potentially be detected with current technology. In addition, a companion in a short period orbit, similar to the orbits of the Galilean moons of Jupiter, would result in relatively frequent transits that could be observed at inclination angles up to ted photometric survey of M and L dwarfs using the robotic infrared telescope PAIRITEL located at Mt. Hopkins, Arizona. The photometric precision and stability of the PAIRITEL infrared photometry will be discussed as well prospects for dealing with the intrinsic variability of the M and L dwarfs by making simultaneous observations in the J, H, and K near-infrared bands. _____________________________________________________________________ Laurent Boisnard (Ctr. Nationale d'Etudes Spatiales, France) The COROT mission : search for extrasolar planets by stellar photometry in low earth orbit The COROT space telescope is an experiment of astronomy dedicated to stellar seismology and search for extrasolar planets. The mission is led by CNES in association with French laboratories and with a significant European participation : ESA and several European countries (Austria, Belgium, Germany, Spain) contribute to the payload or to the ground segment. Brazil is about to join the projet for contribution to the ground segment. Based on a PROTEUS low earth orbit recurrent platform, the spacecraft has been in development since October 2000 for a launch by SOYUZ now scheduled in July 2006. After a series of reviews successfully held and recent payload sub-systems deliveries, the instrument is about to be integrated. At this stage of the project, the purpose of our presentation is to give an overview of the experiment and the associated strategy of research, to explain where the critical scientific requirements are for system engineering and to describe some of the cost-effective compromises found for high accuracy photometry in the specific environment of a low earth polar orbit (altitude : 896 km). In a few words, the experiment is designed for photometry in the visible spectrum, with long continuous observing runs (duration of a run : 150 days) and with two scientific channels working simultaneously on adjacent regions of the sky. The focal plane of the wide field camera is split into two CCD detectors for seismology and two for planet search. As far as this second program is concerned, COROT will be able to detect the presence of extrasolar planets when they pass between the satellite and their parent star. By adapting both the integration time and the focus conditions, it is possible to see some luminous flux variations about 500 ppm, compatible with a transit detection on a large variety of stars (magnitude between 12 and 15.5). Moreover, a prism in the beam of the exoplanet channel produces a chromatic dispersion helpful to discriminate planetary transits against star's surface activity. As a result of its photometric accuracy and duty cycle (higher than 90%), COROT will be able to detect large terrestrial planets (twice the Earth radius) on close-in stellar orbits, Neptune and Uranus-like bodies and many hot Jupiters, expanding the statistics on planetary systems. 12000 target stars in a field of view of 4 square degrees will be simultaneously observed. At least five different regions of the sky (at the intersection of the Equatorial plane and the Galactic plane) will be acquired during the whole mission. _____________________________________________________________________ William Borucki and the Kepler Mission Team (NASA Ames Research Center, Moffett Field, CA 94035) Kepler Mission: Determining the Frequency of Terrestrial Planets in the Habitable Zone of Solar-like Stars Kepler is a Discovery-class mission designed to determine the frequency of Earth-size and larger planets in and near the habitable zone (HZ) of spectral type F through M dwarf stars. The instrument consists of a 0.95 m aperture photometer to do high precision photometry of 100,000 solar-like stars to search for patterns of transits. The depth and repetition time of transits provide the size of the planet relative to the star and its orbital period. Multi-band ground-based observation of these stars is currently underway to estimate the stellar parameters and to choose appropriate targets. With these parameters, the true planet radius and orbit scale, hence the relation to the HZ can be determined. These spectra are also used to discover the relationships between the characteristics of planets and the stars they orbit. In particular, the association of planet size and occurrence frequency with stellar mass and metallicity will be investigated. At the end of the four year mission, several hundred terrestrial planets should be discovered with periods between 1 day and 400 days if such planets are common. A null result would imply that terrestrial planets are rare. Based on the results of the current Doppler-velocity discoveries, over a thousand giant planets will also be found. Information on the albedos and densities of those giants showing transits will be obtained. A brief description of merit function that relates the science value to the mission parameters is included. The Mission is now in Phase C/D development and is scheduled for launch in October 2007 into a 372-day heliocentric orbit. ______________________________________________________________________ Geoff Bryden, C. Beichman, K. Stapelfeldt, M. Werner, T. Gautier (JPL) G. Rieke, D. Trilling, J. Stansberry, K. Su, C. Chen, & the MIPS instrument team (UofA) Debris disk frequency from A to M With the MIPS instrument on Spitzer we have surveyed a broad sample of nearby stars for debris disks. Highlights include: 1) a general decline in 24um debris disk frequency around A stars as a function of age, punctuated by large variations in the magnitude of emission at any epoch, 2) a strong trend toward 70um, rather than 24um, excess emission around G stars (i.e. debris analogous to the Kuiper belt, rather than the asteroid belt), and 3) the detection of debris disks around stars known to harbor planets. _____________________________________________________________________ Andrew Collier Cameron, University of St Andrews Christopher Leigh, Liverpool John Moores University Jean-Francois Donati, Observatoire Midi-Pyrenees Prospects for spectroscopic reflected-light searches with CFHT/ESPaDOnS Past attempts to detect starlight from the atmospheres of close-orbiting giant exoplanets have already set deep upper limits on the albedos and radii of the close-orbiting planets of tau Boo, upsilon And and HD 75289. The geometric albedos of tau Boo b and HD 75289b at visual wavelengths have been shown to be substantially less than that of Jupiter. Here we discuss the prospects for pushing these limits even deeper, using the new fibre-fed echelle spectropolarimeter ESPaDOnS, which has been commissioned at CFHT during the last year. We show that ESPaDOnS' combination of high throughput, high PSF stability, image-slicer geometry and full coverage of the optical spectrum are uniquely well-suited to reflected-light searches involving high-precision spectrum subtraction and line-stacking methods. _____________________________________________________________________ Joseph Carson(NASA JPL) An Adaptive Optics Survey for Brown Dwarf Companions to Stellar Systems I describe here procedures and results for the Cornell High-order Adaptive Optics Survey (CHAOS) for brown dwarf companions to stellar systems. This survey consisted of Palomar 200-inch near-infrared coronagraphic observations of 80 stars out to 22 parsecs. The subsequent data analysis revealed that zero systems showed conclusive evidence for a brown dwarf companion. Accompanying Monte Carlo population simulations determined a brown dwarf companion upper limit of 9.7% for the 25-100 AU semi-major axis region. Such a value indicates, at an 89% confidence level, that the "brown dwarf desert" around stellar objects extends further than has been previously reported. _____________________________________________________________________ Eugene Chiang (Berkeley) Planetary Migration and the Role of Resonances I will review how planets migrate in disks composed either of gas or planetesimals. Migration mechanisms will be considered in the context of our observational understanding of disks. Resonant interactions between planets undergoing migration will be described. Trapping of planetesimals into mean-motion resonances will be discussed as a tool to infer the presence of planets and to diagnose planetary migration. _____________________________________________________________________ John E. Chambers, Carnegie Institution of Washington Oligarchic Growth and the Distribution of Mass in the Planetary System Any successful model for the origin of the Solar System should be able to explain the current distribution of matter in the planetary system as a function of distance from the Sun. In particular, one would like to understand why the mass of condensible material in the outer Solar System is much greater than in the inner Solar System, why the most massive planets lie between 5 and 10 AU from the Sun, why most of the mass in the inner Solar System orbits between 0.7 and 1 AU from the Sun, and why Mars is so much smaller than Earth and Venus. To date, it appears that no model has simultaneously explained all of these aspects. The modern characteristics of the Solar System were determined during the last stages of planet formation, but the final configuration was greatly influenced by what went before, especially the ``oligarchic growth'' phase. During this phase, most of the solid mass in the protoplanetary disk remained in small planetesimals, while the largest object in each region grew rapidly. In the inner Solar System, oligarchic growth probably continued until bodies had masses similar to that of Mars. In the outer Solar System, oligarchic growth may have produced bodies large enough to allow rapid accretion of gas, as invoked in the popular ``core-accretion'' model for the formation of the giant planets. Here I will present simulations of oligarchic growth in the protoplanetary nebula using a new technique in which interactions between protoplanets are treated using an N-body integrator, while the effects of a disk of planetesimals are incorporated in a statistical fashion. The effects of different disk surface density profiles will be investigated, together with the role played by the water-ice condensation front or ``ice line''. I will show that most sets of model parameters, including those commonly used in other works, generally do not lead to a final distribution of mass which is similar to the modern planetary system. _____________________________________________________________________ Gail Chauvin (1); Lagrange, A.-M. (2); Dumas, C. (1); Zuckerman, B. (3); Mouillet, D. (2); Song, I. (3); Beuzit, J.-L. (2) and Lowrance, P (4). (1)ESO, Chili (2)LA, France (3)UCLA (4)Spitzer Science Center VLT/NACO Deep Imaging Search for Brown Dwarf and Giant Planet Companions to Young, Nearby Stars In October 2000 we started a deep coronagraphic imaging survey of young, nearby southern associations, using the ADONIS/SHARPII adaptive optics instrument at the ESO/3.6 m telescope and now, since 2002, NACO at the VLT. This study aims at searching for and characterizing substellar companions, i.e brown dwarfs and giant planets, orbiting young stars. The purpose is then to explore fundamental questions regarding the physical, chemical and orbital properties of substellar companions as well as their origins of formation. After briefly describing the sample surveyed including the range of separation and mass explored, we present recent results, including the discovery of a giant planet companion candidate to the young brown dwarf 2M1207. _____________________________________________________________________ James Y-K. Cho and Sara Seager Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, N.W., Washington, D.C. 20015, USA The Effects of Planetary Rotation Rate on Extrasolar Terrestrial Planet Characterization Planets manifest large ranges in physical properties. One extremely important property is the rotation rate, which has a profound influence on the planet s atmospheric circulation and meteorology hence its characterization. Circulation and meteorology directly control the arrangement of clouds, which affect the planet s temperature, albedo, and spectra at the observable surface , be it the cloud top or the land-ocean surface. Current characterization models account neither for the inhomogeneous distribution of clouds nor the complex interplay between planetary properties, large-scale dynamics, and small-scale meteorology. In this work, we investigate the global dynamics and spectra of Earths with varying rotation rates using a multi-dimensional state-of-the-art general circulation model, coupled with a full spectral model. Our calculations show that the Other Earths can exhibit circulation and cloud patterns similar to that of Venus (single broad band) or Jupiter (multiple narrow bands), depending on the rotation rate. While the outgoing long-wave (emitted planetary) radiation flux is correspondingly changed by the new patterns, the disk-averaged spectra are most sensitive to the orientation of the planet in space i.e., whether the planet is viewed equator-on or pole-on. This work represents a first step in a comprehensive exploration of the wide parameter space of physical properties that influence planet characterization. James Y-K. Cho1, Sara Seager1, Sonali S. P. Shukla2, Kristen Menou3, and Bradley M. S. Hansen4 1 Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, N.W., Washington, D.C. 20015, USA : 2New York University, Andre and Bella Meyer Hall of Physics 4 Washington Pl., New York, NY 10003, USA 3Department of Astronomy, Columbia University, 550 W. 120th Street, New York, NY 10027, USA 4Division of Astronomy, 8971 Math Sciences, UCLA, Los Angeles, CA 90095, USA AB Atmospheric Circulation of Close-In Extrasolar Giant Planets Under Diabatic Heating A large fraction of the more than 130 extrasolar giant planets currently known has orbits that are very close to their host stars. These close-in planets are likely to be tidally locked and thus continuously heated on the same side. Characterizing the atmospheric circulation and temperature distribution on such planets are key issues for both theory and observation. From transit studies, some physical properties crucial for atmospheric modeling (e.g., radius and mass) have been directly measured for several planets. Past modeling studies have focused on flows driven by simple, ad-hoc models of radiative heating and cooling. In this work, we drive the flow with heating rates derived from a full radiative transfer model. The flow model is a high-resolution equivalentbarotropic model, which is capable of resolving the dynamically critical smallscale eddies and waves as well as reproducing the global zonal jet patterns on all four Solar System giant planets. From our extensive set of simulations, we find that, even if the planets rotate slowly (once per ~100 hours), the effects of rotation cannot be ignored: a strong east-west asymmetry is induced by the rotation on a very short timescale (~several hours), leading to a complex heat distribution at early evolution times. At long times (~10 rotation periods), the flow evolves to a state marked by a broad, well-homogenized equatorial zone and a coherent circumpolar vortex at each pole, as in the recent adiabatic calculations of Cho et al. (2003). The stability of the 2 to 3 zonal jet circulation patterns found in the adiabatic calculation is also a robust feature of the present diabatic calculations. Wave breaking activity in the equatorial zone and propagation across the zone is enhanced by the heating strength. In the near future, some of these findings will be directly tested by observations, such as measurements of day-night temperature difference and temporal variations in the IR flux. _____________________________________________________________________ Mark Clampin and the EPIC Science Team The Extrasolar Planetary Imaging Coronagraph (EPIC) The Extrasolar Planetary Imaging Coronagraph (EPIC) is a Discovery class mission concept recently proposed to NASA. EPIC addresses key science themes in the NASA Origins Roadmap, and the President's Vision for Exploration. The mission is designed to provide the first direct measurements of a broad range of fundamental physical characteristics of giant planets in other solar systems. These characteristics include orbital inclination, mass, brightness, color, the presence (or absence) of CH4 and H2O, and orbital or rotational-driven variability. EPIC utilizes a 1.5 meter telescope, coupled to a Visible Nulling Coronagraph to achieve these science goals. EPIC has been proposed as a Discovery Mission concept. We present an overview of the EPIC mission concept, review its science goals and discuss the technical benefits of the EPIC mission design. Mark Clampin, GSFC David R. Ardila, JHU John E. Krist, JPL David A. Golimowski, JHU Holland C. Ford, JHU Garth D. Illingworth, UCSC/Lick ACS GTO Team Recent results from the ACS Science Team's debris disk program We present recent results from the ACS Science Team's program to image debris disks using the Advanced Camera for Surveys (ACS) coronagraphic imaging mode. ACS features a high resolution camera which optimally samples the telescope's point spread function, with a coronagraphic imaging mode. This capability has been employed to obtain multicolor images of debris disks including HD141569A, AU Microscopii, and the first optical images of a disk around the solar type star HD107146. We discuss the scientific highlights of these observations and discuss the results in the context of our current understanding of the formations of planetary systems. _____________________________________________________________________ William D. Cochran, Michael Endl, Barbara McArthur, and Robert Wittenmyer(U Texas) Planet Discoveries With the Hobby-Eberly Telescope The High Resolution Spectrograph on the Hobby-Eberly Telescope is now routinely producing stellar radial velocities with a precision of 2-3 meters/second. This velocity precision, coupled with queue-mode observing, has allowed us to detect planetary companions to two stars: HD 37605 and rho1 Cancri. The companion to HD 37605 has a minimum mass of 2.84 Jupiter masses. The planet is in a 54.23 day orbit of e = 0.737. The queue-scheduled operation of the Hobby-Eberly Telescope enabled us to discover this relatively short-period planet with a total observation time span of just two orbital periods. The extremely low-mass companion to rho1 Cancri is discussed in detail in the separate presentation at this conference by McArthur et al. We present additional recent results from several HET planet detection surveys which demonstrate the unique capabilities of this facility. These include searches for additional extremely low mass planets, and follow-up high precision radial velocity observations of candidate transiting planet host stars. _____________________________________________________________________ Ben Collins (Caltech) The Formation of Terrestrial Planets and Ice Giants We investigate the growth of proto-planets in a solar system using an N-body scheme optimized for bodies on nearly circular orbits. This routine evolves the orbital elements according to mutual interactions as well as any additional forces. We then add accurate expressions for dynamical friction and planetesimal accretion, and allow the proto-planets to coagulate. We simulate this proto-planetary disk from the last stages of oligarchy into the unstable regime that follows. _____________________________________________________________________ Curtis S. Cooper and Adam P. Showman (U Arizona) Atmospheric dynamics of the transiting exoplanet HD 209458b In this work, we use a primitive equation model adapted from the atmospheric sciences to simulate the dynamics of the atmosphere of HD 209458b within the radiative zone, which extends to ~1 kbar at the object's estimated age of 5.1 Gyr. The simulations employ a scheme for Newtonian cooling to approximate the radiative transfer. In this scheme, the temperature field is relaxed to the temperature profile in radiative equilibrium. We present simulations demonstrating the flow geometry for a range of assumptions about the radiative equilibrium temperature profile. Our simulations show---in general agreement with the predictions of Showman \& Guillot (2002)---fast equatorial jets of $\rm \sim$5 $\rm km s^{-1}$ at altitude (10-1000 mb), which approach or exceed the speed of sound in the fluid. At these low pressures, the hottest regions of the atmosphere are blown downwind from the substellar point where the planet receives the highest irradiation. Deeper down ($\rm >$10 bars), wind velocities decrease and the equatorial jet gives way to a weak meridional flow and relatively uniform temperature profile. The simulations show a 400 K day-night temperature difference at 1 bar, with the peak in temperature at about 100 degrees longitude downstream from the substellar point. This temperature difference leads to a phase difference of over a day between the time of the optical transit and the time of peak infrared emission from the planet, which is in principle measurable with sufficiently sensitive instruments. We diagnose the energy and angular momentum budgets of the planet and test the hypothesis that the object's evolution has been affected by the dissipation of atmospheric kinetic energy into the deep interior. We note, however, that the integration times of our simulations are relatively short compared to the radiative relaxation timescale at high pressures, so that the total kinetic energy of the atmosphere once it reaches steady-state will be significantly larger than our simulations predict. This research is supported by NSF grant AST-0206269, NASA Ames Research Center Cooperative Agreement (NCC 2-5518), and NASA GSRP NGT5-50462. _____________________________________________________________________ Justin Crepp (U Florida) Laboratory Testing of High-order Image Masks for TPF-C We have built and tested the first 8th-order and 12th-order binary notch filter image masks. These masks combine a suite of advantages for high-contrast imaging and demonstrate key technologies for the Terrestrial Planet Finder Coronagraph (TPF-C). In particular, they substantially relax telescope pointing requirements and are less sensitive to low-order optical aberrations compared to 4th-order masks. We report results of their performance with monochromatic and broadband light in the Space Astronomy Instrumentation Lab (SAIL) - TPF testbed, at the University of Florida. _____________________________________________________________________ W.C. Danchi(1), R. Barry (1), J. Rajagopal(2), R.J. Allen(2), D.J. Benford(1), D. Deming(1), D.Y. Gezari(1), M. Kuchner(3), D.T. Leisawitz(1), R. Linfield(4), J.D. Monnier(6), L.G. Mundy(7), C. Noecker(4), L.J. Richardson(1), S. Seager(8), W.A. Traub(3), D. Wallace(1) (1) NASA Goddard Space Flight Center (2) Space Telescope Science Institute (3) Harvard-Smithsonian Center for Astrophysics (4) Ball Aerospace (5) California Institute of Technology (6) University of Michigan (7) University of Maryland (8) Carnegie Institution of Washington The Fourier-Kelvin Stellar Interferometer (FKSI): A progress report The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for an imaging and nulling interferometer for the near-infrared to mid-infrared spectral region (3-8 microns). FKSI is conceived as a scientific and technological pathfinder to TPF/DARWIN as well as SPIRIT, SPECS, and SAFIR. It will also be a high angular resolution system complementary to JWST. The scientific emphasis of the mission is on the evolution of protostellar systems, from just after the collapse of the precursor molecular cloud core, through the formation of the disk surrounding the protostar, the formation of planets in the disk, and eventual dispersal of the disk material. FKSI will also search for brown dwarfs and Jupiter mass and smaller planets, and could also play a very powerful role in the investigation of the structure of active galactic nuclei and extra-galactic star formation. We report additional studies of the imaging capabilties of the FKSI with various configurations of two to five telescopes, studies of the capabilities of FKSI assuming an increase in long wavelength response to 10 or 12 microns (depending on availability of detectors), and preliminary results from our nulling testbed. _____________________________________________________________________ John Debes (Penn State) Searching for Planets Around White Dwarfs White dwarfs, the stellar remnants of stars between 1-8 M$_\odot$, represent a unique population to look for extrasolar planetary companions. They are orders of magnitude fainter than their progenitors and any putative companions have adiabatically expanded their orbits, becoming easier to separate from the glare of their host white dwarf. We present the latest results from a high contrast imaging campaign of nearby white dwarfs that uses the NICMOS coronagraph on the Hubble Space Telescope, PUEO/KIR on the Canada France Hawaii Telescope, and Altair/NIRI on the Gemini North Telescope. We discuss several candidate companions as well as avenues for future work. _____________________________________________________________________ Drake Deming (1), Timothy M. Brown (2), David Charbonneau (3), Joseph Harrington (4), and Jeremy Richardson (1) (1)NASA GSFC (2)High Altitude Observatory/National Center for Atmospheric Research, Boulder (3)Harvard CfA (4)Cornell A New Search for Carbon Monoxide Absorption in the Transmission Spectrum of the Extrasolar Planet HD 209458b We have revisited the search for carbon monoxide absorption features in transmission during the transit of the extrasolar planet HD 209458b. In August-September 2002 we acquired a total of 1077 high resolution spectra (resolving power 25,000) in the K-band (2 micron) wavelength region using NIRSPEC on the Keck~II telescope during three transits. These data are more numerous and of better quality than the data analyzed in an initial search by Brown et al. Our analysis achieves a sensitivity sufficient to test the degree of CO absorption in the first overtone bands during transit, based on plausible models of the planetary atmosphere. We analyze our observations by comparison to theoretical tangent geometry absorption spectra, computed by adding height-invariant ad hoc temperature pertubations to the model atmosphere of Sudarsky et al., and by treating cloud height as an adjustable parameter. We do not detect CO absorption. The strong 2-0 R-branch lines between 4320 and 4330 wavenumbers have depths during transit less than 1.6 parts in 10,000 in units of the stellar continuum (3 sigma limit), at a spectral resolving power of 25,000. Our analysis indicates a weakening similar to the case of sodium, suggesting that a general masking mechanism is at work in the planetary atmosphere. Under the interpretation that this masking is provided by high clouds, our analysis defines the maximum cloud top pressure (i.e., minimum height) as a function of the model atmospheric temperature. For the relatively hot model used by Charbonneau et al. to interpret their sodium detection, our CO limit requires cloud tops at or above 3.3 mbar, and these clouds must be opaque at a wavelength of 2 microns. High clouds comprised of submicron-sized particles are already present in some models, but may not provide sufficient opacity to account for our CO result. Cooler model atmospheres, having smaller atmospheric scale heights and lower CO mixing ratios, may alleviate this problem to some extent. However, even models 500K cooler that the Sudarsky et al. model require clouds above the 100 mbar level to be consistent with our observations. Our null result therefore requires that clouds exist at an observable level in the atmosphere of HD 209458b, unless this planet is dramatically colder than current belief. _____________________________________________________________________ Ian Dobbs-Dixon, UC Santa Cruz, 813.459.2774 Spin-Orbit Evolution of Short-Period Planets The negligible eccentricity of all extrasolar planets with periods less than 6 days can be accounted for by dissipation of tidal disturbances within their envelopes that are induced by their host stars. In the period range of 7-21 days, planets with circular orbits coexist with planets with eccentric orbits. These are referred to as the borderline planets. We propose that this discrepancy can be attributed to the variation in spin-down rates of young stars. In particular, prior to spin-down, dissipation of a planet's tidal disturbance within the envelope of a sufficiently rapidly spinning star can excite eccentricity growth and, for a more slowly spinning star, at least reduce the eccentricity-damping rate. In contrast, tidal dissipation within the envelope of a slowly spinning low-mass mature star can enhance the eccentricity-damping process. On the basis of these results, we suggest that short-period planets around relatively young stars may have a much larger dispersion in eccentricity than those around mature stars. We also suggest that because the rate of angular momentum loss from G and K dwarfs via stellar winds is much faster than the tidal transfer of angular momentum between themselves and their very short (3-4 days) period planets, they cannot establish a dynamical configuration in which the stellar and planetary spins are approximately parallel and synchronous with the orbital frequency. In principle, however, such configurations may be established for planets (around G and K dwarfs) with orbital periods of up to several weeks. In contrast to G and K dwarfs, the angular momentum loss due to stellar winds is much weaker in F dwarfs. It is therefore possible for synchronized short-period planets to exist around such stars. The planet around Tau Boo is one such example. _____________________________________________________________________ U. Dyudina (1), P.Sackett(2), D. Bayliss(2), L Dones(3), H. Throop(3), C. Porco(4), S. Seager(5) (1)Caltech (2)Australian National University, Canberra, Australia (3)SWRI,Boulder (4)CICLOPS/Space Science Institute,Boulder (5)DTM,CIW, Washington Phase Light Curves for Extrasolar Jupiters and Saturns We predict how a remote observer would see the brightness variations of giant planets similar to those in our Solar System as they orbit their central stars. We model the geometry of Jupiter, Saturn and Saturn's rings for varying orbital and viewing parameters. Scattering properties for the planets and rings at wavelenghts 0.6-0.7 microns are assumed to follow these observed by Pioneer and Voyager spacecraft, namely, planets are forward scattering and rings are backward scattering. Images of the planet with or without rings are simulated and used to calculate the disk-averaged luminosity varying along the orbit, that is, a light curve is generated. We find that the different scattering properties of Jupiter and Saturn (without rings) make a substantial difference in the shape of their light curves. Saturn-size rings increase the apparent luminosity of the planet by a factor of 2-3 for a wide range of geometries, an effect that could be confused with a larger planet size. Rings produce asymmetric light curves that are distinct from the light curve of the planet without rings, which could resolve this confusion. If radial velocity data are available for the planet, the effect of the ring on the light curve can be distinguished from effects due to orbital eccentricity. Non-ringed planets on eccentric orbits produce light curves with maxima shifted relative to the position of the maximum planet's phase. Given radial velocity data, the amount of the shift restricts the planet's unknown orbital inclination and therefore its mass. Combination of radial velocity data and a light curve for a non-ringed planet on an eccentric orbit can also be used to constrain the surface scattering properties of the planet and thus describe the clouds covering the planet. To summarize our results for the detectability of exoplanets in reflected light, we present a chart of light curve amplitudes of non-ringed planets for different eccentricities, inclinations, and the viewing azimuthal angles of the observer. _____________________________________________________________________ A. Eggenberger (1), G. Chauvin (2), S. Udry (1), J.-L. Beuzit (3), A.-M. Lagrange (3), (1)Obs. Geneve, Switzerland (2)ESO (3)LAG, France WHAT DO OBSERVATIONS TELL US? We have undertaken a systematic adaptive optics search for (faint) close stellar companions to nearby dwarf stars, some of them known to harbour a planet, the others thought to be single, for comparison. This survey aims at investigating several fundamental, yet open questions regarding the occurrence of planets in binary and multiple star systems: what is the global effect of stellar duplicity on planet formation and subsequent evolution? Are the properties of planets found in binaries different from the ones of planets orbiting single stars? Are there many giant planets in "close" binaries? In this contribution we will present the current results of our survey, which is nearing completion. We will also discuss how stellar duplicity can be used to test planet formation models and possibly discriminate between them. _____________________________________________________________________ Josh Eisner (Caltech) Probing Sub-AU Radii of Young Circumstellar Disks The structure of young circumstellar disks, and in particular of the regions within 1 AU of the central star, has important implications for disk accretion and planet formation. We have observed a sample of T Tauri and Herbig Ae/Be stars with the Keck and Palomar Testbed Interferometers, supplemented by echelle spectroscopy and optical through near-IR photometry. With these data, we constrain the geometries and temperatures of inner circumstellar dust disks, and compare our measurements with the predictions of physical disk models. Analyzing our measured inner disk properties with those expected for magnetospheric accretion models, we find evidence that gaseous disk material extends further in toward the star than dust. We compute the expected orbits for migrating giant planets halted in 2:1 resonances with the inner disk, and compare these with the observed semi-major axis distribution of extra-solar planets. Finally, we discuss implications for terrestrial planet formation. _____________________________________________________________________ Michael Endl(1), William D. Cochran(1), Diane B. Paulson(2), Phillip J. MacQueen(3), Robert G. Tull(1) (1)U Texas (2)NASA GSFC (3)High Altitude Observatory, National Center for Atmospheric Research, Boulder "A Low Frequency Of Close-In Giant Planets Around M Dwarfs" We present high precision radial velocity data for a sample of 81 M dwarf obtained with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m Telescope at McDonald Observatory, as well as the Keck I Telescope on Mauna Kea to search for giant planetary companions. None of the stars show variability indicative of a giant planet in a short period orbit. The M dwarfs included in our survey have thus a frequency of close-in giant planets of < 1.2%. So far, GJ 876 remains the only unambiguous case of an M dwarf orbited by Jupiter-class planetary companions. This might indicate an overall low incidence of giant planets in the low mass part of the HR-diagram. _____________________________________________________________________ Eric B. Ford (UC Berkeley) Increasing the Sensitivity of Planet Searches with Dynamic Scheduling High-precision radial velocity planet searches have surveyed $\sim\!2000$ nearby stars and detected $\sim\!130$ planets. While these same stars likely harbor many additional planets, they will become increasingly challenging to detect, as they tend to have relatively small masses and/or relatively long orbital periods. Therefore, observers are increasing the precision of their observations, continuing to monitor stars over decade timescales, and also preparing to survey thousands more stars. Given the considerable amounts of telescope time required for such observing programs, it is important use the available resources as efficiently as possible. Previous studies have found that a wide range of predetermined scheduling algorithms result in planet searches with similar sensitivities. We have developed adaptive scheduling algorithms which have a solid basis in Bayesian inference and information theory and also are computationally feasible for modern planet searches. We have performed Monte Carlo simulations of plausible planet searches to test the power of adaptive scheduling algorithms. Our simulations demonstrate that planet searches performed with adaptive scheduling algorithms can simultaneously detect more planets, detect less massive planets, and measure orbital parameters significantly more accurately than comparable surveys using a non-adaptive scheduling algorithm. We expect that these techniques will be particularly valuable for the N2K radial velocity planet search for short-period planets, as well as future astrometric planet searches with the Space Interferometry Mission which aim to detect terrestrial mass planets. _____________________________________________________________________ H. Ford (JHU), W. Sparks (STScI), and R. White (STScI) An ACS Coronagraphic Search for Planets Around Alpha Cen A & B ACS High Resolution Camera coronagraphic images of Alpha Cen A and B were taken with a sequence of intermediate band filters at two different epochs. The filter bandpasses and wavelengths were chosen such that the observations could be analyzed with spectral deconvolution. We present the results from two independent approaches to analyzing the observations and dealing with the presence of the second star (B or A) that is in the field of view. We compare our detection limits as this stage in the data analysis to the magnitudes expected for gas giants that are within the zones of stable orbits around A and B. _____________________________________________________________________ J.J. Fortney & M.S. Marley (NASA Ames Research Center) Reflection Spectra of Extrasolar Giant Planets: New Models and Optimized Filter Calculations Using a model atmosphere code that has been applied extensively to planets and brown dwarfs, we compute pressure-temperature profiles and reflection spectra of extrasolar giant planets (EGPs) at a variety of orbital distances and gravities. With an eye towards optical coronagraphic imaging, we compute the locations and widths of medium- and wide-band filters that will allow for first-order characterization of EGP atmospheres with a minimum of integration time. We compute magnitudes and colors for these models in a variety of filters and compare the model-derived values to those of our solar system's giant planets. For instance, we find that that the spectral signature of water clouds, which form below Teff ~ 300 K, leads to a significant change in spectral slope that is easily detectable with only two wide-band filters. We also discuss how photochemically-derived hazes, which are found in the stratospheres of all the solar system's giant planets, may complicate efforts to characterize EGP atmospheric properties. _____________________________________________________________________ Ovidiu Furdui and Rainer Spurzem Astronomisches Rechen-Institut, Heidelberg, Germany Dynamical Evolution of Planets with Belt Interaction The orbital evolution and stability of planetary systems with interaction from the belts is studied using the standard phase-plane analysis. The belt is assumed to have power-law density prowhich corresponds to the Keplerian orbit, there are other edges of the belt. The existence of these orbital circularization due to frictional force from the belt. It is interesting that we found a limit cycle of semi-attracter. Our results show that for the planets, the probability to move stably around the inner edge is larger than the one to move around the outer edge. It is also interesting that there is a limit cycle of semi-attractor for a particular case. Applying our results to the Solar System, we a natural mechanism to do the orbit rearrangement for the larger Kuiper Belt Objects and thus successfully explain the absence of these objects beyond 50 AU. _____________________________________________________________________ Jian Ge, Department of Astronomy, The University of Florida All Sky Extrasolar Planet Survey with Sloan Telescope A decade-long, all-sky, extrasolar planet survey at the Sloan 2.5 meter wide field telescope is being planned for monitoring 1,000,000 stars with V = 8-13 in the solar neighborhood with a goal to detect 100,000 extrasolar planets between 2008-2020. This survey is enabled by a new generation multiple object Doppler radial velocity instrument based on a dispersed fixed-delay interferometer called Exoplanet Tracker (ET). The instrument capable of simultaneously observing hundreds of stars increases the planet survey speed by more than two orders of magnitude over current single object echelle instruments. One channel of the instrument is designed for monitoring F, G, K type stars in the visible, the other channel is designed for monitoring M type stars in the near infrared aiming at detection of habitable planets. Following the commissioning of the first multiple object instrument at Sloan in March and April 2005, a pilot program will be carried out to monitor 20,000 stars with V = 8 -11 in 2005-2008. Currently a trial survey with a single object ET is being conducted with the KPNO 0.9 meter Coude telescope. Initial survey results will be reported. ______________________________________________________________________ Andrea Ghez (UCLA) TBD ______________________________________________________________________ Brett Gladman and Collin Chan University of British Columbia A rogue planet scenario for the creation of the Extended Scattered Disk. The extended scattered disk (trans-neptunian objects with large semimajor axes and eccentricities but perihelia above about 40 AU) seems to require a cosmogonic explanation becuase scattering off the current giant planets cannot produce these objects in sufficient numbers. Stellar encounter scenarios appear feasible, although they require the correct encounter timing, distance, and angle to produce the observations. We present results of numerical simulations which show that scenarios in which there were additional `rogue planets' in the outer Solar system (with masses of order 10 percent of Uranus) which efficiently raise perihelia of scattered disk objects during the first 100-200 Myr of the Solar System's history before being eliminated from the System. _____________________________________________________________________ C.A. Grady, the STIS GTO, HST GO 9136 Team, and the HST GO 10177 Team High Contrast Imaging of Protoplanetary Disks: The STIS and NICMOS Perspective We present the results of high contrast coroaagraphic imaging surveys of protoplanetary disks including both classical T Tauri stars and Herbig Ae stars with HST STIS and, an on-going survey with NICMOS. The white-light STIS coronagraph covered 0.2-1.0 microns and was sensitive to remnant envelopes, bipolar jets and chains of HH knots, as well as reflection nebulosity from the disks. The observed disk surface brightness spans at least 2 orders of magnitude at 2 arcsec from the star. The optical surface brightness of the large disks correlates with the strength of the mid-IR PAH features, as seen by ISO, for the Herbig Ae stars. Some of the classical T Tauri stars have both coronagraphic imagery and FUV long-slit spectra. The optical surface brightness of the nebulosity around these stars appears to correlate with the strength of the spatially extended fluorescent molecular hydrogen emission. This trend may also be present among the Herbig Ae stars, albeit for an extremely small sample. While the NICMOS survey is still underway, the stars which have been observed to date suggest that a similar trend is present in the near-IR. Both the PAH emission and the molecular hydrogen fluorescence require direct illumination of the emitting material by a FUV light source. For comparatively isolated PMS stars, such as have been imaged with HST, such a source is the PMS star itself. The optically bright disks are those, therefore, with flared disk surfaces, while the dark disks in the sample are consistent with disks with constant opening angle or those which are geometrically flatter. Two disks in the sample have inner zones which are dark, and outer, brighter rings, suggesting that the dark zones are a byproduct of grain settling and subsequent dissoiation or removal of macromolecules and molecular gas. _____________________________________________________________________ J H Hough(1) , P W Lucas (1), J A Bailey (2), E Hirst (3) (1)Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB, England (2) Anglo-Australian Observatory, Epping Laboratory, PO Box 296, Epping NSW 2121, Australia (3) Particle Instruments Group, Science & Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB, England PLANETPOL: A new polarimeter for the direct detection & characterization of scattered light from extra-solar planets The advantages of using polarimetry to make direct detections of the light from extra-solar planets are discussed. The performance of a polarimeter with sufficient sensitivity to make such direct detections is presented together with some preliminary data from observations of stars with known extrasolar planets. _____________________________________________________________________ Nader Haghighipour (University of Hawaii) Formation of habitable planets in binary star systems. Current models of planet formation, explain how planets are formed around single stars. However, binary stars are the most common outcome of the star formation process. There is also considerable evidence for protoplanetary disks in young multiple star systems. Observations show that initial conditions for planet formation exist in binary star systems, as well. A survey of all currently known extrasolar planets indicates that close to 25% of their hosting stars are members of binary systems. Almost all of these binaries are wide with separations ranging from 250 to 1000 AU. At these separations the effect of the binary companion on the formation of planets around the other star is negligible. However, in close binary systems, the gravitational perturbation of the companion can have considerable effects on the structure of the circumstellar disk, formation of planetesimals and protoplanets, and ultimately on the formation of habitable planets, and water-delivery mechanisms. In this paper, I will present results of simulations of the dynamical evolution of planetesimals around one of the stars of a binary, and discuss the effects of the companion on the formation of Earth-like planets in the habitable zone of such a star. The implication of type II runaway growth of such simulations is that terrestrial planet embryos, and thus habitable planets, can form in protoplanetary disks in the presence of a massive binary companion. Within the context of habitability, I will present the results of a large survey of the parameter space of binary-planetary systems in search of regions where habitable planets can have long-term stable orbits, and will also discuss the effect of the companion on mechanisms of delivery of water to such planets. _____________________________________________________________________ Lynne Hillenbrand (Caltech) TBD _____________________________________________________________________ Matthew J. Holman (1), Norman W. Murray (2) 1: Harvard-Smithsonian Center for Astrophysics 2: Canadian Institute for Theoretical Astrophysics, University of Toronto The Use of Transit Timing to Detect Extrasolar Planets Future surveys for transiting extrasolar planets, including the space-based mission Kepler (Borucki et al 2003), are expected to detect hundreds of Jovian mass planets and tens of terrestrial mass planets. For many of these newly discovered planets, the intervals between successive transits will be measured with an accuracy of 0.1--100 minutes. We show that these timing measurements will allow for the detection of additional planets in the system (not necessarily transiting), via their gravitational interaction with the transiting planet. The transit time variations depend on the mass of the additional planet, and in some cases Earth-mass planets will produce a measurable effect. In some cases, when two or more planets transit the same star, the densities of the planets can be estimated. _____________________________________________________________________ Keith Horne, St.Andrews University Colin Snodgrass, Queens' University Belfast An Optimal Strategy for the RoboNet-1 Microlens Planet Survey Intensive monitoring of the lightcurves of Galactic Bulge microlens events is probably the fastest way to discover `cool planets' in 1-10 AU orbits around late-type stars with sensitivity to small planets approaching the mass of the Earth. In 2004 over 600 such events were identified by the OGLE-III and MOA experiments, and the lightcurves of several dozen of these were followed up using 1-m class telescopes coordinated by the PLANET, microFUN and MOA teams. In 2005, the UK RoboNet-1 experiment will augment PLANET's microlens follow-up network by linking three 2m robotic telescopes: the Liverpool Telescope in La Palma, Canary Islands and the two Faulkes Telescopes in Maui, Hawaii and Siding Springs, Australia. With limited observing time and so many events underway, observers face a non-trivial dilemma in deciding which events to observe and for how long on each night. RoboNet's robotic telescopes require fully automatic algorithms. I describe a metric and optimisation scheme for allocating observing time among ongoing events, designed to maximise the probability of detecting new planets. Cool planet detection capabilities of telescopes employing this strategy are investigated using Monte-Carlo simulations. _____________________________________________________________________ Hannah Jang-Condell (Carnegie) How Shadowing and Illumination in Disks Affects Planet Formation Radiative transfer is an important process in protoplanetary disks. Stellar illumination, in particular, is primarily responsible for setting the temperature and density structure of passively accreting protoplanetary disks. Perturbations in the structure of a disk such as clumping, gap-opening, and dust-settling can create shadows and bright spots which in turn further perturb the disk's structure. Density and temperature variations resulting from the dynamical interactions between a planet and a disk can be further enhanced by these cooling and heating effects, leading to alterations in planetary migration rates, planetary growth, and other important planet formation processes. I present radiative transfer calculations on a three-dimensional disk perturbation induced by a protoplanet. These temperature perturbations can affect ice formation vis-a-vis the "snow line" which in turn affects the accumulation of water onto a planet embryo as well as the growth rate of protoplanets. The change in the local pressure gradient caused by these temperature perturbations also changes the migration rate of the planet. I will also address some possible observational signatures of the presence of planets in disks. Small planets which are insufficiently massive to open a full annular gap in the disk are likely to be out of the range of observability, but gaps with large extent may be detectable in images and SEDs. _____________________________________________________________________ Ray Jayawardhana (University of Toronto) Disks Around Young Brown Dwarfs and Potential for Planet Formation I will review recent findings by our group and others on the frequency and characteristics of disks around young very low mass stars and brown dwarfs, covering the entire mass range from just above the hydrogen burning limit all the way to primary masses approaching the planetary domain. I will also present some new results on accretion, jets, disk masses and disk lifetimes, and discuss the potential for planet formation around sub-stellar objects. _____________________________________________________________________ John A. Johnson UC Berkeley Geoff Marcy UC Berkeley Debra Fischer San Francisco State Universtity Searching For Planets Orbiting Subgiants The vast majority of planet-bearing stars have masses less than 1.3 solar, due to the target selection criteria in Doppler searches. Main sequence stars more massive than 1.3 solar masses tend to be fast rotators, have fewer spectral lines and display a large amount of atmospheric ``jitter.'' One method to circumvent these difficulties is to observe stars after they evolve off of the main sequence. These subgiant stars are ideal planet search targets because they are cooler and rotate slower than their main-sequence, F- and A-type progenitors. We present a Doppler survey of a sample of 200 subgiants in order to determine whether or not stars with masses between 1.3 and 2.5 solar harbor planets, and whether the occurrence rate of planets is dependent upon the mass of the host star. _____________________________________________________________________ Hugh Jones (University of Hertfordshire NOT Liverpool John Moores University as originally registered) The Anglo-Australian Planet Search The Anglo-Australian Planet Search is a long-term programme being carried out on the Anglo-Australian Telescope to search for giant planets aroun nearby Solar type stars. We began observing in January 1998 observing 200 target stars over 20 nights per year, and have very recently grown to more than 60 nights per year targetting an expanded sample. Twenty planet candidates with M sin i values ranging from 0.2 to 10 Mjup have been found from the programme, four planet candidates have been confirmed using our data and several found by other programmes disputed. Our precision Doppler velocity measurements are made with the an echelle spectrograph with an iodine absorption cell. The iodine cell enables us to achieve measured long-term velocity stability of 2 m/s (for suitably stable stars) down to our survey magnitude limit. This stability will be discussed in the context of our latest results and our announcement of the HD70642 system (the best 'Solar System' analog yet found). _____________________________________________________________________ Paul Kalas (UCB), James Graham (UCB), and Mark Clampin (NASA GSFC) New HST images of dust belts around nearby main sequence stars. We present new HST optical data that resolve debris disks around nearby A - K stars with ages betwen 0.2 and 1 Gyr. In all cases, structure is belt-like, with evidence of azimuthal and radial asymmetry that can be linked to planetary perturbations. The large radii of the inner edges - two to three times that of our Kuiper Belt - flag systems where dynamical scattering or migration may have increased the semi-major axes of extrasolar Neptunes. In the best resolved example, the sharpness of the inner and outer belt boundary can be measured and related to theoretical calculations of disk-planet dynamical interactions. _____________________________________________________________________ Stephen Kane (St Andrews, UK) Hunting for Extra-Solar Planets in the Draco Field with the WASP Prototype The Wide Angle Search for Planets prototype (WASP0) is a wide-field instrument used to search for extra-solar planets via the transit method. Here we present the results of a monitoring program which targeted field stars in Draco. This programme involved the monitoring of around 35000 field stars for a period of two consecutive months. We describe the transit detection algorithm used to extract transit candidates from the thousands of lightcurves that have been produced. Analysis of the lightcurves resulted in the detection of 11 multi-transit candidates and 3 single-transit candidates, two of which we recommend for further follow-up. Monte-Carlo simulations which match the observing parameters have been performed to estimate the expected number of transit candidates from this survey. A comparison of the expected number with the number of candidates detected is used to discuss limits on planetary companions to field stars. _____________________________________________________________________ L.D. Keller(1), G.C. Sloan(2), K.I. Uchida(2), E. Leibensperger(1), W.J. Forrest(3), J. Najita(4), C. H. Chen(5), J. D. Green(3), F. Kemper(6), D. M. Watson(3), L. Hartmann(7), T. L. Herter(2), N. Calvet(7), P. D'Alessio(8), E. Furlan(2), B. Sargent(3), P. Morris(5), D. J. Barry(2), P. Hall(2), B. R. Brandl(9), P. C. Meyers(7), and J. R. Houck(2) (1)Ithaca College (2)Cornell University (3)University of Rochester (4)National Optical Astronomy Observatory, Tucson (5)California Institute of Technology (6)UCLA (7)CfA, Harvard (8)UNAM, Mexico (9)Sterrewacht Leiden, Netherlands Mid-infrared spectroscopy of emission from polycyclic aromatic hydrocarbons around Herbig AeBe stars We present Spitzer Infrared Spectrograph observations of 4 Herbig AeBe stars including HD 141569. All of the sources exhibit strong emission from polycyclic aromatic hydrocarbons (PAH) in the 5-20 micron range; in some of the spectra PAHs dominate the emission. A detailed examination reveals variations in the relative contributions of the skeletal PAH modes (6-8 microns), the C-H bending modes (8-13 microns). The variations in strengths between skeletal and C-H bending modes suggests variations in ionization ratios of the PAHs in our sample. Since AeBe stars are commonly characterized by strong crystalline silicate emission in this spectral region, we also examine the relative contributions (and possible confusion) of silicate and PAH features in the spectra of our sample of stars. _____________________________________________________________________ Stephan Kellner (Max-Planck-Institut for Astronomy, Heidelberg) Spectral Differential Imaging - How close are we imaging an extra solar planet? Speckle Noise is one of the most limiting factors in order to detect companions close (< 1") to a young star by the means of Adaptive Optics systems. We present here a method to reduce speckle noise by using differential imaging techniques of simultaneously obtained frames around the methane absorption band at 1.62 microns. We give a brief overview about the technical aspects, introduce furthermore a particularly for this application developed data reduction pipeline. Moreover we show very promising results obtained by oberserving several nearby young stars. We discuss both the enormous potential of Spectral Differential Imaging and also its limitations in terms of detection limits. _____________________________________________________________________ Hubert Klahr and Anders Johansen Max-Planck-Institute for Astronomy, Heidelberg Dust Diffusion, Transport and Concentration in 3D MHD Simulations of Protoplanetary Accretion Disks It is of great importance to understand the transport and mixing properties of turbulence in protoplanetary accretion disks. First, diffusion directly influences the chemical evolution in the disk and has an impact on the growth of dust particles to planetesimals. As a result the transport of dust grains and molecules determines the observational features of the disk. As a first order approach one usually assumes the diffusion parameter to be exactly equal to the turbulent viscosity. We demonstrate in how far this assumption is justified. Therefore, we study the transport of small grains in a direct numerical simulation of turbulence in a protoplanetary accretion disk driven by the magneto rotational instability. We adopt the Pencil code in a shearing sheet approximation to measure the diffusion properties of the disk turbulence in relation to the measured Reynolds and Maxwell stresses. We find the diffusion to be anisotropic and show how it relates to the measured stresses. We also study the transient concentration of solids in the turbulent flow pattern and the implications on the formation of planetesimals. _____________________________________________________________________ David Koch, William Borucki, J. Lissauer, David Mayer, Janice Voss, NASA Ames Research Center, Moffett Field, CA, Gibor Basri, Alan Gould, Univ. California-Berkeley, Berkeley, CA, Timothy Brown, High Altitude Observatory, Boulder, CO, Douglas Caldwell, Edna DeVore, Jeff Garside, Jon Jenkins, SETI Institute, Mountain View, CA, William Cochran, Univ. Texas-Austin, Austin, TX Edward Dunham, Lowell Observatory, Flagstaff, AZ, Nick Gautier, Jet Propulsion Laboratory, Pasadena, CA, John Geary, David Latham, Smithsonian Astrophysical Observatory, Cambridge, MA, Yoji Kondo, Goddard Space Flight Center, Greenbelt, MD, David Monet, US Naval Observatory, Flagstaff, AZ, Eric Bachtell, Jeff Baltrush, William Deininger, Adam Harvey, Lorna Hess-Frey, Dan Peters, Mike Weiss, Ball Aerospace and Technologies Corp., Boulder, CO, Riley Duren, Jet Propulsion Laboratory, Pasadena, CA, Rick Thompson, Orbital Sciences Corp., Mountain View, CA, Kepler Mission Design The Kepler Mission is in the development phase with launch planned for 2007. The primary mission goal is to reliably detect a significant number of Earth-size planets in the habitable zone of solar-like stars. (See W. Borucki, this conference.) The mission design allows for exploring the diversity of planetary sizes, orbital periods, stellar spectral types, etc. (also see papers by D. Latham and G. Basri, this conference) In this paper we describe the technical approach taken for the mission design; describing the flight and ground system, the detection methodology, the photometer design and capabilities, and the way the data are taken and processed. Finally the detection capability in terms of planet size and orbit are presented as a function of mission duration and stellar type. _____________________________________________________________________ Eiichiro Kokubo (National Astronomical Observatory of Japan) Protoplanets to Terrestrial Planets We investigate the formation process of terrestrial planets from protoplanets by using N-body simulations. As the initial conditions we adopt the oligarchic growth model of protoplanets. We derive the statistical properties of the resultant terrestrial planets from the results of about 100 runs. We show the dependence of the mass and orbital properties of the terrestrial planets on the mass and distribution of the initial protoplanets. The formation probability of habitable planets is also discussed. _____________________________________________________________________ Maciej Konacki, Caltech Precision radial velocities of double-lined spectroscopic binaries and the search for extrasolar planets in binary stellar systems A spectroscopic technique employing an iodine absorption cell (I_2) to superimpose a reference spectrum onto a stellar spectrum is currently the most widely adopted approach to obtain precision radial velocities (RVs) of solar-type stars. It has been used to detect ~80 extrasolar planets out of ~130 know. Yet in its original version, it only allows us to measure precise radial velocities of single stars. I will present a novel method employing an I_2 absorption cell that enables us to accurately determine radial velocities of both components of double-lined binaries. Initial results based on the data from the Keck~I telescope and HIRES spectrograph demonstrate that 20-30 m/s radial velocity precision can be routinely obtained for "early" type binaries (F3-F8). For later type binaries, the precision reaches ~10 m/s. I will discuss my ongoing search for extrasolar planets in binary stellar systems and the application of the new technique to stellar astronomy. In particular, such RVs when combined with the interferometric data collected with the Palomar Testbed Interferometer can routinely produce masses of the binary components accurate at the level of 0.1 to 1.0 % and challenge modern models of stellar structure and evolution. ____________________________________________________________________ Marc Kuchner (Princeton University) and Sara Seager (Carnegie DTM) Extrasolar Carbon Planets We suggest that extrasolar planets $\sim$1--60~$M_{\bigoplus}$ may commonly form substantially from carbon and silicon carbide like carbonaceous chondrites. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk's C/O ratio above solar, a condition that the evaporation of interstellar organics may create interior to where the temperature reaches 350~K in some protoplanetary disks. These planets may be distinguished by hydrocarbon-rich spectra and tar-covered surfaces. Diamond shells can protect these planets from carbon depletion at high temperatures and high fluxes of ionizing radiation. The planets around pulsar PSR 1257+12 or the newly discovered close-in Neptune-mass planets may represent this new class of carbon planets. Marc Kuchner and Andrew Youdin (Princeton University) Matthew Bate (University of Exeter) Delivery of Water to the Terrestrial Planets Via Ice Grains Following a Shifting Snow Line Protoplanetary disks evolve through a stage when viscous heating flags yet dust opacity still shields the midplane from direct sunlight. During this cold phase late in the evolution of the solar nebula, water likely condensed from the nebula and fell onto Earth, Venus and Mars as millimeter-sized ice grains. We investigated the flow of grains through the nebula onto protoplanets and planetesimals using analytic and numerical models and calculate grain capture probabilities as a function of protoplanet mass and orbital eccentricity. Our models support water-rich beginnings for Mars and Venus, and they predict a systematic, rather than stocastic, distribution of water-rich extrasolar planets. In this distribution, $\sim 1 M_{\bigoplus}$ planets have a larger mass fraction of water than larger or smaller bodies and planets on more eccentric orbits receive more water. Besides delivering the Earth's water, this mechanism can also supply the nitrogen in the Earth's atmosphere and the noble gasses in Jupiter's envelope, though some low-temperature condensates found in the inner solar system may still require comets or asteroids to supply them. _____________________________________________________________________ David W. Latham (CfA), Timothy M. Brown (HAO), Mark E. Everett (PSI), and David G. Monet (USNOFS) Target Selection for the Kepler Mission Kepler will stare at more than 100,000 solar-type stars continuously for four years to look for transits by earth-sized planets. Because of limited access to the Deep Space Network for data transmission, only the CCD pixels that include selected targets will be returned to Earth for analysis. Magnitude-limited samples are dominated by hot stars and giants that are too large to allow the detection of earth-sized transits. Therefore the Kepler team has undertaken a photometric and spectroscopic survey of the Kepler target region, more than 150 square degrees in Cygnus and Lyra, to provide the information needed for the selection of optimum targets. The multi-band CCD photometry is being carried out with the 48-inch telescope at the Whipple Observatory on Mount Hopkins, Arizona, using SDSS filters supplemented by a Mg b filter. Spectroscopy of candidate targets identified by the photometry will be carried out with the Hectochelle multi-fiber spectrograph on the MMT. The goal is to provide effective temperatures, metallicities, reddening, extinction, and surface gravities so that stellar radii can be estimated. Radial and rotational velocities will be reported for those stars that are observed spectroscopically. The resulting Kepler Input Catalog containing on the order of 10 million stars is scheduled for delivery in December 2006. _____________________________________________________________________ Gregory Laughlin(1), Peter Bodenheimer(1), Fred Adams(2) (1)University of California (2)University of Michigan The Core Accretion Model Predicts few Jovian-Mass Planets will be found Orbiting M-Dwarfs The favored theoretical explanation for giant planet formation -- in both our solar system and others -- is the core accretion model (although it still has some serious difficulties). In this scenario, planetesimals accumulate to build up planetary cores, which then accrete nebular gas. With current opacity estimates for protoplanetary envelopes, this model predicts the formation of Jupiter-mass planets in 2--3 Myr at 5 AU around solar-mass stars, provided that the surface density of solids is enhanced over that of the minimum-mass solar nebula (by a factor of a few). Working within the core-accretion paradigm, we present theoretical calculations which show that the formation of Jupiter-mass planets orbiting M dwarf stars is seriously inhibited at all radial locations (in sharp contrast to solar-type stars). Planet detection programs sensitive to companions of M dwarfs will test this prediction in the near future. _____________________________________________________________________ T. Joseph W. Lazio (Naval Research Laboratory), Jill C. Tarter (SETI Institute), D. J. Wilner (Center for Astrophysics) The Square Kilometer Array and The Cradle of Life The Square Kilometer Array (SKA) is a unique radio telescope being designed by an international consortium with the aim of surpassing the capabilities of the current generation of radio telescopes by at least an order of magnitude. By virtue of its sheer sensitivity (10^6 m^2 collecting area), high frequency coverage (at least to 25 GHz), and long baselines (~ 3000 km), the SKA will play a pivotal role in astrobiological studies. With its frequency coverage, the SKA will be sensitive to emission from dust grains with sizes of order 1 cm, thereby probing a crucial stage in the assembly of planets. With its sensitivity and long baselines, the SKA will be able to *image* proto-planetary disks in nearby star-forming regions and even monitor the evolution of structures within those disks (``movies of planetary formation''). Finally, it will also be able to assess the extent to which interstellar molecules are incorporated into proto-planetary disks. Basic research in radio astronomy at the NRL is supported by the Office of Naval Research. T. Joseph W. Lazio, Naval Research Laboratory William M. Farrell, NASA/GSFC Planetary Magnetospheres, Planetary Habitability, and Direct Detection of Extrasolar Planets By virtue of their planetary-scale magnetic fields, the Earth and all of the gas giants in our solar system possess solar-wind deformed magnetospheres. The magnetic polar regions of these ``magnetic planets'' produce intense, aurora-related radio emission from solar-wind powered electron currents. In the case of the Earth, its magnetic field also shields its atmosphere and surface from cosmic rays, potentially playing a key role in making its surface habitable. We describe a combined theoretical and observational program designed to test the extent to which auroral radio emission from the known extrasolar planets may be detectable over interstellar distances. Various forms of a radiometric Bode's Law have been developed to describe the dependence of auroral radio emission upon a planet's distance from the Sun and its magnetic moment. We have applied a typical form for the radiometric Bode's Law to the current census of extrasolar planets. We predict that the auroral radio emission of the known extrasolar planets may be within reach of current radio telescopes, under favorable circumstances, and should definitely be detectable with future instruments. We are also conducting a systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array. The current limits set by the VLA images are approaching, but do not yet provide strong constraints on, the predictions of the model. Basic research in radio astronomy at the NRL is supported by the Office of Naval Research. _____________________________________________________________________ Man Hoi Lee (UCSB) On the 2:1 Orbital Resonance in the HD 82943 Planetary System We present an analysis of the HD 82943 planetary system based on a radial velocity data set that combines new measurements obtained with the Keck telescope and the published CORALIE measurements.We examine simultaneously the goodness of fit and the dynamical properties of the best-fit double-Keplerian model as a function of the poorly constrained eccentricity and argument of periastron of the outer planet's orbit. There are two local minima of comparable $\chi_\nu^2$, but they are both dynamically unstable if the orbits are assumed to be coplanar. However, the minima are relatively shallow, and there is a wide range of fits outside the minima with reasonable $\chi_\nu^2$. For an assumed coplanar inclination $i = 30^\circ$ ($\sin i = 0.5$), only the good fits with both of the lowest order, eccentricity-type mean-motion resonance variables at the 2:1 commensurability, $\theta_1$ and $\theta_2$, librating about $0^\circ$ are stable. For $\sin i = 1$, there are also some good fits with only $\theta_1$ librating that are stable for at least $10^4$ years. The libration amplitudes are about $10^\circ$ (or less if $\sin i < 1$) for the stable good fit with the smallest libration amplitudes of both $\theta_1$ and $\theta_2$. Thus the two planets in the HD 82943 system are almost certainly in 2:1 orbital resonance, with at least $\theta_1$ librating, and may even be consistent with small-amplitude librations of both $\theta_1$ and $\theta_2$. _____________________________________________________________________ Zoe Leinhardt (University of Maryland) Out of the rubble: The growth of protoplanets We present results from a dozen direct N-body simulations of terrestrial planet formation with various initial conditions. In order to increase the realism of our simulations and investigate the effect of fragmentation on protoplanetary growth, we have developed a self-consistent planetesimal collision model that includes fragmentation and accretion of debris. In our model we treat all planetesimals as gravitational aggregates so that gravity is the dominant mechanism determining the collision outcome. We compare our results to those of Kokubo and Ida (2002) in which no fragmentation is allowed---perfect merging is the only collision outcome. After 500,000 yr of integration our results are virtually indistinguishable from those of Kokubo and Ida (2002). We find that the number and masses of protoplanets, and time required to grow a protoplanet, depends strongly on the initial conditions of the disk and is consistent with oligarchic theory. We have determined that the elastistity of the collisions, which is controlled by the normal component of the coefficient of restitution, does not significantly affect planetesimal growth over a long timescale. Particles below our resolution limit (debris) are treated semi-analytically, and we find that planetesimals accrete debris faster than they are ground down. As a result, at the end of oligarchic growth the debris component it negligible and does not affect the dynamics of the protoplanets. _____________________________________________________________________ Doug Lin (UCSC) The Mass-Period Relation of Extra Solar Giant Planets. Based on the convensional sequential accretion scenario, we consider the growth of planetesimals to cores and protoplanetary embryos in a gaseous medium. In disks with similar mass distribution as the minimum mass nebula, cores may attain sufficiently large masses to induce the onset of efficient gas accretion beyond he snow line. But, in more massive disks, gas giants may form in broad regions including locations interior to the snow line. Gas accretion is terminated by the local clearing through gap formation and global depletion due to photo evaporation. Based on the observed distribution of disk mass and disk migration models, we determine a mass-period distribution for systems with single gas giant planets. We show the dependence of this distribution for a range of stellar metallicity and masses. We predict the existence of a desert of planets with modest masses and intermediate periods. We also show that abundance of currently observable gas giants rapidly increases with stellar metallicity and masses, which is consistent with the observational results. _____________________________________________________________________ Charles H. Lineweaver(1) and Daniel Grether(2) (1)Planetary Science Institute, Australian National University, Canberra, ACT, Australia (2)Department of Astrophysics, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia How Dry is the Brown Dwarf Desert?: Quantifying the Relative Number of Planets, Brown Dwarfs and Stellar Companions around Nearby Sun-like Stars The formation of a binary star via molecular cloud collapse and fragmentation, and the formation of a massive planet around a host star via protoplanetary disk accretion, both involve the production of a binary system, but are recognized as distinct processes. The formation of companion brown dwarfs with masses in between the stellar and planetary mass ranges may have elements of both, or some more distinct mechanism. To constrain and differentiate models of the formation of these companions, we analyse the close companions ($P < 5$ years) of nearby Sun-like stars ($d < 25$ pc & $d < 50$ pc). By using the same sample to extract the relative numbers of stellar, brown dwarf and planetary companions, we are able to verify the existence of the brown dwarf desert and decribe it quantitatively. The mass function drops by more than an order of magnitude from $1.0 M_{\odot}$ stars to the brown dwarf mass range and rises by approximately half an order of magnitude as we move from brown dwarfs to Jupiter mass objects. The companion mass function in the brown dwarf and stellar mass range, has a different shape than the mass function of single stars and free-floating brown dwarfs. We discuss the possible origins of this difference in terms of formation mechanisms or post-formation migratory processes. _____________________________________________________________________ Michael C. Liu (U Hawaii) Debris Disks around M Dwarfs The vast majority of stars are the low-mass M dwarfs, but these objects have been relatively neglected in studies of disk and planet formation. At very young ages, low mass stars commonly have primordial disks; however, little is known about their subsequent evolution. We discuss the observed paucity of debris disks around low mass objects in the solar neighborhood compared to disks around higher mass stars. We then highlight the one well-studied M dwarf debris disk around the young star AU Mic. By virtue of the star's proximity (10 pc) and youth (12 Myr), multi-wavelength infrared and sub-millimeter observations achieve excellent sensitivity of the dust content and detailed morphology. We compare the AU Mic disk to other known young debris disk systems, and consider its properties in the context of current models of planet formation. Characterization of the AU Mic disk provides new insight into the physical nature of the long-studied archetype beta Pictoris. These two systems likely represent a key phase in disk evolution, between the primordial disks around pre-main sequence stars and the very tenuous debris disks around old stars. _____________________________________________________________________ James Lloyd (Cornell University), Mark Swain (Laboratoire d'Astrophysique Observatoire de Grenoble) Vincent Coude du Foresto (LESIA/Observatoire de Paris-Meudon) Wesley Traub, (Harvard-Smithsonian Center for Astrophysics) Christopher Walker, (University of Arizona) John Storey (University of New South Wales) The Antarctic Plateau Interferometer The Antarctic Plateau Interferometer (API) is an instrument concept capable of extensive unique discovery space science in a variety of areas including exoplanets, accretion, YSO's, and AGNs. To study exoplanets in the habitable zone, API would use three 2 meter class telescopes, high-dynamic range spectroscopy, and differential closure phase to achieve 1:1e5 contrast ratio measurements. API would achieve this performance using proven technology at the best accessible site on Earth for infrared interferometry. At Dome C Antarctica, the combination of low levels of atmospheric turbulence (resulting in the best seeing ever measured) and low thermal background enable an interferometer with 2 m class telescopes to exceed substantially the performance of existing instruments. API will be packaged in shipping containers so that the instrument can be demonstrated on the sky in the northern hemisphere and then shipped, with a minimum of disassemble, to Dome C. The combination of using existing interferometer technology (adapted to the Antarctic environment) and containerized packaging makes it possible to begin operation at Dome C in 5 years. In addition to delivering a high-impact science program, API could test instrument technology for space interferometry missions such as Darwin and TPFI. _____________________________________________________________________ Christophe Lovis, Michel Mayor, Stephane Udry (Obs. Geneve, Switzerland) Searching for extrasolar planets around red giants in intermediate-age open clusters We present preliminary results from our radial-velocity survey of ~50 red giants in the clump of 8 open clusters in the southern sky. The data have been obtained with the CORALIE spectrograph at La Silla and extend over more than one year. Cluster membership allows precise knowledge of red giant masses, which are very uncertain for field red giants. The age of the clusters (200 Myr to 4 Gyr) involves red giant masses between 3.7 and 1.3 M_Sun, allowing us to explore a new primary mass domain in the search for extrasolar planets. Interestingly, the radius reached by these giant stars at the RGB tip is not a strong limitation to the existence of short-period planets. Low-mass companions should be able to survive around 2 M_Sun giants for periods as short as ~40 days. The main limitation to this research will be the stellar RV jitter, which is poorly understood for giant stars. Our first results show that two thirds of the stars have a radial-velocity dispersion below 50 m/s, with a peak at about 25 m/s. We discuss the dependence of the RV dispersion on the position in the H-R diagram. We also present a few promising candidates, among which a possible 2 M_Jup planet around a 2.4 M_Sun star. _____________________________________________________________________ Phil Lucas, University of Hertfordshire and P F Roche, U Oxford A Gemini survey of the bottom of the IMF in the Trapezium Cluster We present the results of a deep imaging survey of the Trapezium Cluster with Gemini South/Flamingos. The survey is sensitive to objects with masses as low as 2 to 4 Jupiter masses, this limit being subject to significant theoretical uncertainties in the mass-luminosity relation. The mass function for luminosity selected brown dwarf candidates is found to decline into the planetary mass regime, though the slope of the decline depends on the presently unknown degree of contamination by background stars among the faintest sources. The incidence of wide binaries is found to be lower in brown dwarfs than in stars with a modest statistical significance. Some probable wide star+brown dwarf binaries are detected at separations too small for a chance association. However these pairs exist in apparent small-N groups which may be dynamically unstable, so the results do not necessarily conflict with the ejected stellar embryo hypothesis of Reipurth & Clarke. _____________________________________________________________________ Kevin Luhman (Harvard CfA) Spitzer Observations of Brown Dwarf Disks Through the GTO programs of the Spitzer IRAC, MIPS, and IRS instrument teams, we are obtaining extremely sensitive mid-infrared photometry and spectroscopy of circumstellar disks around a large sample of young low-mass stars and brown dwarfs in nearby star-forming regions. By combining these data with the predictions of models of circumstellar disks, we constrain various properties of these disks, such as their geometries (flat or flared?), inner radii, dust compositions, and lifetimes. With these results, we address the fundamental issue of how circumstellar disks -- and hence the initial conditions of planet formation -- change from stars to brown dwarfs. _____________________________________________________________________ Bruce Macintosh (LLNL)and James Graham (U California/Berkeley and U California/Santa Cruz) Direct Detection of Extrasolar Planets with Adaptive Optics on 8-30m telescopes Current radial-velocity searches for extrasolar planets, though powerful, are fundamentally constrained in the range of orbits they can access by the need for a near-complete orbital period: the largest detectable semi-major axis only grows with time to the 2/3 power. In the next several decades, indirect detection will barely reach planets with orbits comparable to Saturn. However, planets in our solar system exist at wider separations (such as Neptune, with an orbital period of 164 years). Resolves extrasolar dust disks frequently exceed 100 AU, some with evidence for perturbing planets in wide orbits. To probe the 5-100 AU range different techniques are needed. Direct detection of photons emitted by extrasolar planets is one such technique, but requires contrast levels of 10^7 (for warm self-luminous planets) to 10^9 for mature Jupiter analogs. Adaptive optics technology has matured to the point where it is now possible to design systems that can achieve contrast >10^7 on 8-10m telescopes. I will review the key issues in designing such a system, and present Monte Carlo simulations that show their likely science reach. Studies of the planet population in this region will shed considerable light on the mechanisms of planet formation and migration. In the next decade, even larger telescopes such as the Thirty Meter Telescope (TMT) will be operational. Such telescopes can achieve even higher contrasts, but will be operating in competition with space-based planet imaging missions such as TPF-C. To justify a planet-detection AO system for TMT we must identify a compelling scientific role that exploits the advantages of extremely large filled-aperture telescopes. I will present a comparative analysis of TPF and TMT for Jovian planet detection. One mission for which TMT could excel is imaging of the planet formation process - exploiting the high angular resolution and small inner working distance of a 30-m telescope to probe ~5 AU scales in nearby star forming regions. _____________________________________________________________________ Jean-Luc Margot (Cornell University) HST observations of binary Kuiper Belt Objects (KBOs) Our Hubble Space Telescope (HST) program is designed to characterize the orbital and physical properties of six confirmed KBO binaries [Margot et al., 2003]. Our primary goals are to measure the masses/densities of KBOs, to identify the binary formation mechanism, and to place constraints on the primordial Kuiper belt. The densities of large Kuiper belt objects provide estimates of the ice/rock fraction which depends on the amount of Oxygen sequestered in CO in the early solar nebula. The range of densities admissible by the new Oxygen abundances of Asplund et al. differs considerably from previous estimates. Most KBOs in our sample must have high albedos, otherwise their densities would be implausibly low. For unit density, we find that KBOs in our sample have albedos in the range 8-40%, much higher than indicated by the long-held assumption that KBOs have comet-like albedos of ~4%. This implies that the total mass in the Kuiper belt may have been over-estimated by an order of magnitude. The size distribution of KBOs must similarly be revised to account for the smaller, brighter objects. The high albedos presumably require a continuous collisional resurfacing in the Kuiper Belt. The binary formation mechanisms proposed to date make important predictions for the characteristics of the binaries and the environment at the time of formation. The distributions of semi-major axes, eccentricities, and inclinations of the binary pairs available to date do not appear to support the binary formation of model of Funato et al. nor that of Goldreich et al. References Asplund et al., A&A 417, 2004. Funato et al., Nature 427, 2004. Goldreich, Lithwick, Sari, Nature 420, 2002. Margot, Brown, Trujillo, Sari, HST General Observer Prgm 9746, 2003. _____________________________________________________________________ Barbara McArthur et al. McArthur, Barbara E.(1); Endl, Michael(1); Cochran, William D.(1); Benedict, G. Fritz(1); Fischer, Debra A.(2); Marcy, Geoffrey W.(2); Butler, R. Paul(3); Naef, Dominique(4); Mayor, Michel(5); Queloz, Diedre(5); Udry, Stephane(5); Harrison, Thomas E.(6) (1)U Texas (2)Berkeley (3)Carnegie Institution of Washington (4)San Francisco State University (5)Obs. Geneve, Switzerland (6)New Mexico State University Detection of a Neptune-Mass Planet in the ?1 Cancri System Using the Hobby-Eberly Telescope We report the detection of the lowest mass extrasolar planet yet found around a Sun-like star-a planet with an Msini of only 14.21+/-2.91 M? in an extremely short period orbit (P=2.808 days) around ?1 Cancri, a planetary system that already has three known planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner planet at 0.04 AU. We estimate an inclination of the outer planet ?1 Cancri d, based on Hubble Space Telescope Fine Guidance Sensor measurements that suggest an inner planet of only 17.7+/-5.57 M?, if coplanarity is assumed for the system. _____________________________________________________________________ Renu Malhotra (Arizona) TBD _____________________________________________________________________ Geoff Marcy (Berkeley) TBD _____________________________________________________________________ Mark Marley, Jonathan Fortney, Olenka Hubickyj, Jack Lissauer (NASA Ames Research Center), Peter Bodenheimer (UC Santa Cruz) Young Jupiters are Faint The early evolution of young extrasolar giant planets is of considerable interest. EGPs are brightest and most easily detectable when they are young. However traditional planet evolution models, which progress from arbitrarily hot and extended initial states, are unreliable at young ages. Despite modelers? impassioned caveats, the lack of alternatives has led various tabulations of model luminosities for young planets to be routinely used to plan observations and estimate detectability of these objects at ages of less than twenty or so million years. This model shortcoming led our group to produce the first self-consistent evolutionary calculation for a one Jupiter-mass planet including all stages of formation, accumulation, and subsequent cooling. Our calculations include the accretion of an approximately ten Earth mass core followed by the subsequent rate-limited flow of nebular gas onto that core. After the total planet mass reaches 1 MJ accretion is terminated and the planet begins to cool adiabatically, as in standard cooling sequences. Since the evolutionary calculation begins with a planet that has been self-consistently brought to its initial state, we believe the behavior at young ages is more reliable than previous computations. We find that while our total luminosity agrees well with other models at ages in excess of about 30 million years, at younger times our predicted luminosity is substantially?by up to a factor of two or more?lower. This result implies that extrasolar giant planets around very young stars may be substantially more difficult to detect than expected. We will present our evolution calculation as well as model spectra and photometry of young EGPs. _____________________________________________________________________ Eduardo Martin (UCF) Title: Detection of planets around ultracool dwarfs: present and future Abstract: We will report on ongoing observational efforts to detect planets around ultracool dwarfs using radial velocity and imaging techniques. Results on ultracool dwarf binaries will be shown, including dynamical mass measurements and binary frequencies. We will also discuss the status of planet candidates. We will present the NAHUAL project, which is a high-resolution near-infrared echelle spectrograph for the 10.4-meter telescope in La Palma (GTC). We estimate that this instrument will reach the required sensitivity to detect planets down to a few earth masses in the habitable region around ultracool dwarfs. _____________________________________________________________________ Francisco Javier Martin-Torres (NASA LRC) Is the OH a key-species to look for in our search for life in other planets? Meinel[1] first identified the bright airglow in the night sky as produced by the emission from the rotational-vibrational bands of hydroxyl (OH). The emission from these bands has been subsequently observed in oxygen-supported flames and stellar atmospheres[2], interstellar medium[3], comets[4,5] and other astronomical objects[6,7]. In the Earth's atmosphere the two most important sources of OH are the reactions of hydrogen (H) and ozone (O3) and the photolysis of water vapour (H2O)[8]. Both are exothermic reactions and the rotational and vibrational levels of OH formed and responsible of the visible and infrared emissions, have excitation temperatures that differ from the local kinetic temperature. This implies that the assumption that they emit according to the Planck function at the local kinetic temperature is no longer valid and non- Local Thermodynamic Equilibrium (non-LTE) models must be used to simulate and analyze them[9]. In the near future new optical and infrared spectral separation techniques will help us to analyze spectra from exoplanetary atmospheres. The detection of OH in a planetary atmosphere using those spectra would be an indirect evidence of the presence of ozone and water vapour (and, perhaps, life). Nevertheless OH is not a key-species the current proposed missions to search and characterize exoplanets as the Terrestrial Planet Finder[10]. Here, based on the analysis of the measurements of the OH emissions in the atmosphere of the Earth taken by space-borne instruments is evaluated the potential non-LTE OH emissions in the visible and infrared. This is an important issue to deal with in order to perform an appropriate design of future missions. REFERENCES: [1] Meinel, I.A. B., OH Emission Bands in the Spectrum of the Night Sky, Astrophysical Journal, vol. 111, p.555-568, (1950) [2] Grevesse, N, Sauval, A. J. and van Dishoeck, E. F., An analysis of vibration-rotation lines of OH in the solar infrared spectrum, Astronomy and Astrophysics (ISSN 0004-6361), vol. 141, no. 1, Dec. 1984, p. 10-16 (1984) [3] Robinson, B. J. and McGee, R. X., OH Molecules in the Interstellar Medium, Annual Review of Astronomy and Astrophysics, vol. 5, p.183-197 (1967). [4] Meisel, D. D. and Berg, R.A., High resolution spectrophotometry of selected features in the 1.1 micron spectrum of Comet Kohoutek-1973f, Icarus, vol. 23, Nov. 1974, p. 454-458 (1974). [5] Tozzi, G. P., Feldman, P. D., and Weaver, H. A., Observations of the OH Meinel system in comet P/Swift-Tuttle, Astron. Astrophys. 285L, L9-L12 (1994) [6] Lewis, B. M., David, P., Le Squeren, A. M., Mainline OH detection rates from blue circumstellar shells, Astronomy and Astrophysics Supplement, v.111, p.237 (1995) [7] Sylvester et al., Detection by ISO of the far-infrared OH maser pumping lines in IRC+10420, Royal Astronomical Society, Monthly Notices, vol. 291, p. L42-L46 (1997) [8] Brasseur, G. and Solomon, S. Aeronomy of the Middle Atmosphere, 2nd ed., D. Reidel Publishing Co., Norwell, Mass. (1986) [9] Mlynczak, M. G.and Solomon, S., Middle atmosphere heating by exothermic chemical reactions involving odd-hydrogen species, Geophysical Research Letters (ISSN 0094-8276), vol. 18, p. 37-40 (1991) [10] NASA's Terrestrial Planet Finder mission: the search for habitable planets, Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22-25 April 2003, Heidelberg, Germany. Edited by M. Fridlund, T. Henning, compiled by H. Lacoste. ESA SP-539, Noordwijk, Netherlands: ESA Publications Division, ISBN 92-9 ns Division, ISBN 92-9 _____________________________________________________________________ Michel Mayor et al.(Obs. Geneve, Switzerland) SEARCHING FOR VERY LOW MASS PLANETS The one meter/second precision for the radial velocity measurements currently achieved with the HARPS spectrograph is well adapted to explore the exoplanet mass domain below the mass of Saturn. Several exoplanets have already been detected with masses as small as Neptune's mass. These detections could add constraints on the formation of exoplanets by comparison with statistical predictions recently proposed by several teams. _____________________________________________________________________ Tsevi Mazeh(1), Omer Tamuz(1), Shay Zucker(2) & Andrzej Udalski(3) (1)Tel-Aviv, Israel (2)Obs. Geneve, Switzerland (3)European Southern Observatory, Germany Sys-Rem - A new Algorithm to Remove Systematic Effects in Large Photometric Datasets: Application to OGLE Carina Lightcurves with New Transit Candidates We constructed a new algorithm, Sys-Rem, to remove systematic effects in a large set of lightcurves obtained by a photometric survey. The algorithm can remove any systematic effects, like the ones associated with atmospheric extinction, detector efficiency, or PSF changes over the detector. Sys-Rem works without any prior knowledge of the effect, as long as it linearly appears in many stars of the sample. The algorithm, which was originally developed to remove atmospheric extinction effects, is based on a lower rank approximation of matrices. It is specially useful in cases where the uncertainties of the measurements are unequal. For equal uncertainties Sys-Rem reduces to the Principal Components Analysis (PCA) algorithm. Application of Sys-Rem to the OGLE Carina dataset revealed new significant transit candidates. _____________________________________________________________________ Stanimir Metchev and Lynne Hillenbrand (Caltech) Low-Mass Companions to Young Solar Analogs We present preliminary results from a coronagraphic survey of young nearby Sun-like stars using the Palomar and Keck adaptive optics systems. We have targeted 251 solar analogs (F5-K5) at 20-160 pc from the Sun, spanning the 3-3000 Myr age range. The youngest (<500 Myr) of these have been imaged with deeper exposures to search for sub-stellar companions. The deep survey of 100 stars is sensitive to brown-dwarf companions at separations >0.5" from their host stars, with sensitivity extending to planetary-mass (5-15 Jupiter masses) objects at wider (>3") separations. Based on the discovery of a number of new low-mass (<0.2 solar masses) stellar companions, we infer that their frequency at >20~AU separations may be greater (12%) than that found from radial velocity surveys probing <4 AU separations (6%; Mazeh et al. 2003). In addition to revealing the multiplicity of Sun-like stars at wide separations and low binary mass ratios, this survey may also help guide future radial velocity studies of the planetary frequency around binary stars, that can then be compared with the emerging results on single stars. Finally, we report the astrometric confirmation of the first sub-stellar companion from the survey - an L4 brown dwarf at a projected distance of 44 AU from the 500 Myr-old star HD 49197. Based on this detection, we estimate that the frequency of sub-stellar companions to solar-type stars is at least 1%, and possibly of order a few per cent. _____________________________________________________________________ C. McCarthy, D. Fischer (San Francisco State Univ.), G. Marcy (U.C. Berkeley) Search for Terrestrial Planets with the Space Interferometry Mission The Space Interferometry Mission will return unprecedented astrometric precision of 1 microarcsecond, enabling the detection of planets with masses few times the mass of the Earth around the nearest stars. With launch in 2010, SIM will discover and provide dynamical masses for the planets observed by Terrestrial Planet Finder. To achieve 1 microarcsecond precision in narrow angle mode, SIM requires an exquisitely stable reference frame established by distant background stars, all within 1 degree of each target star to be searched for planets. We present the current status of SIM's search for extrasolar terrestrial planets. _____________________________________________________________________ Caer-Eve McCabe(1), A.M. Ghez(1), L. Prato(1) & G. Duchene(2) (1)UCLA (2)Grenoble Observatory T Tauri Disk Evolution A high spatial resolution, 10-20 micron, survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis has been carried out at the Keck telescope. Combined with resolved near-infrared photometry and spectroscopic accretion diagnostics, the survey probes the inner ~AU region of the circumstellar disks around these young stars and finds that ten percent of stars with a mid-infrared excess do not appear to be accreting. In contrast to an actively accreting disk system, these 'passive disks' have significantly lower K-L colors that are, in most cases, consistent with photospheric emission, suggesting the presence of an inner disk hole. In addition, there appears to be a significant mass dependence associated with the presence of a passive disk, with all passive disks having spectral types later than M2.5. The presence of a companion does not appear to be related to the presence of an inner disk hole; the passive disks sample the entire range of binary separations present in the sample and a similar fraction of passive disks is observed in a sample of single stars. The mass dependence makes the possibility that the passive disks are caused by the presence of a nearby, as yet unresolved, companion unlikely, and suggests that these passive disks represent a subset of T Tauri stars that are in the process of losing their disk material, with the disk evolving in an inside-out manner. In this framework, the timescale of disk evolution appears to be dependent on the mass of the central star, with disks around low mass stars taking longer to clear out the inner disk region. Caer-Eve McCabe, Gaspard Duchene, Andrea Ghez, Francois Menard, Christophe Pinte, Karl Stapelfeldt (UCLA-JPL-Grenoble team) Resolving the structure and grain size distribution of T Tauri disks through multi-wavelength Monte Carlo simulations of scattered light images. Resolved scattered light images of T Tauri circumstellar disks, in combination with dust thermal emission maps in the millimeter regime, provide a powerful tool that can be used to probe the grain sizes in these young, presumably protoplanetary, systems. By obtaining spatially resolved scattered light observations over as wide a wavelength range as possible on systems where the disk structure and mass is well constrained, we can investigate the wavelength dependence of the dust scattering properties and, in the case of disks which are close to edge-on, the vertical disk structure. Using the Keck II Adaptive Optics system with NIRC2, the facility near-infrared camera, we have spatially resolved the GG Tau, HK Tau and HV Tau circumstellar disks in scattered light in the 3-5 micron wavelength range. The angular dependence of scattered light at these wavelengths does not behave as expected from standard ISM dust models, with the disks consistently showing evidence for more forward throwing dust at longer wavelengths. Multi-wavelength Monte Carlo modeling of these systems finds evidence for larger than ISM grain sizes and, in at least two of these cases, evidence for dust settling. _____________________________________________________________________ Stanimir Metchev (Caltech), Joshua Eisner (Caltech), Lynne Hillenbrand (Caltech), Sebastian Wolf (MPI) Structure and Dynamical Evolution in the AU Mic Disk We present adaptive optics observations of the near-IR scattered light from the inner 17-60 AU of the AU Mic disk. We find evidence for clumpy disk sub-structure, confirming previous observations, suggestive of the existence of embedded planets. However, no >1 Jupiter-mass planets are detected at >20 AU separations from the star. We also observe a reddening trend in the color of the scattered light with decreasing disk radius, indicating the presence of larger grains at smaller orbital separations. Using a radiative transfer code to simultaneously model the optical to near-IR scattered light surface brightness profile and the optical to sub-mm spectral energy distribution, we constrain the disk mass, minimum and maximum grain sizes, and the inner radius of the disk. We then compare the equally-young AU Mic and beta Pic systems and observe similar radial structure in the two debris disks: both exhibit chages in the power-law of their scattered light profiles over a discrete range of disk radii. From a scaling anlysis of the physical parameters of the two systems, we conclude that the observed homology is the signature of either grain growth or Poynting-Robertson drag in circumstellar disks undergoing a transition between a primordial and a debris state. These processes self-consistently explain the observed radial dependence of the grain size in the AU Mic disk. Thus, the comparative study of the co-eval and homologous AU Mic and beta Pic debris disks provides more accurate empirical constraints on the relevant dynamical time-scales in circumstellar disks than previously possible from analyses of individual systems. _____________________________________________________________________ Amaya Moro-Martin (U Arizona) Signatures of planets in debris disks Main sequence stars are commonly surrounded by debris disks, composed of cold far-IR emitting dust presumably generated by a reservoir of undetected dust-producing planetesimals. In debris disks harboring massive planets, the trapping of dust in gravitational resonances with the planet creates a density enhancement in a ring-like structure outside the orbit of the planet, while gravitational scattering with the planet creates a clearing of dust inside the planet's orbit. Massive planets, therefore, can create structure in the dust disk, and the study of this structure can help us survey a range of planetary parameters that are not detected by other methods. The Spitzer infrared space telescope will obtain spatially unresolved spectrophotometric observations of many potentially diverse debris disk systems with embedded planets. We discuss how the structure carved by massive planets affects the shape of a debris disk's spectral energy distribution (SED), and consequently how the SED may be used to infer the presence and properties of planets. We show that the SED modeling presents some degeneracies that can only be broken if spatially resolved images of the dust disks are obtained. _____________________________________________________________________ M. Nagasawa(1), E. Thommes(2), & D. N. C. Lin(1) (1)UCSC (2)CITA, University of Toronto Final accretion of terrestrial planets and depletion of asteroids We calculated the orbital evolution of protoplanets and planetesimals during the protoplanetary disk depletion including effects of the tidal drag and gas drag. The estimated total mass in the asteroid belt inferred from observations is only 0.1% of that from the mass distribution of the minimum mass solar nebula. This cannot be accounted for only by planetary configurations. We found a sweeping secular resonance passes through a region of terrestrial planets during the dissipation of disk and that the resonance excites eccentricities of protoplanets and planetesimals and causes their orbits to cross. The excited eccentricities of large protoplanets are damped by the tidal drag and the eccentricities of small particles are damped by gas drag. This damping induces semi-major axes to decay. Therefore, the protoplanets tend to migrate along with the secular resonance and several circular terrestrial planets are formed inside 2AU. Since the effect of the sweeping secular is strong in a region of asteroids, the resonance combined with the tidal drag or gas drag can clear up the asteroids. _____________________________________________________________________ Eric Nielsen (1), Laird Close (1), Rainer Lenzen (2), Jose Guirado (3), Eric Mamajek (4), Wolfgang Brandner (2), Markus Hartung (5), Chris Lidman (5), Beth Biller (1). The First Observational Calibration of Theoretical Cooling Curves for Young, Low-Mass Objects. 1: Steward Observatory, University of Arizona 2: Max-Plank Institut fur Astronomie 3: Departament d'Astronomia i Astrofisica, Universitat de Valencia 4: Harvard-Smithsonian Center for Astrophysics 5: European Southern Observatory Simultaneous Differential Imaging (SDI) is a promising technique to image low-mass, close companions, and our team is undertaking a survey to detect extrasolar planets around a sample of nearby, young stars. Using NACO SDI at the VLT, we have detected a new low-mass companion, 5.4 magnitudes fainter at H than the primary, at a separation of just 0.156 arcseconds. Follow-up JHK photometry gives absolute magnitudes for the new companion of J=9.89 (+0.19, -0.24), H=9.19 (+0.13, -0.15), and Ks=8.57 (+0.12, -0.15), and K-band spectra give a spectral type of M8 (+/- 1.0). From these values, combined with the age of the primary of 50 Myr, and a mass derived from an astrometric orbit of 0.090 (+/- 0.005) solar masses, it is clear that the currently used models (Burrows et al. 2001 and Chabrier et al. 2000) systematically underestimate the mass of young, low-mass objects by about a factor of two. This is a profound result, as young, cool objects may have higher masses than have been reported, and it's likely that "cluster planets," young free-floating objects of planetary mass, are actually just low-mass brown dwarfs. _____________________________________________________________________ Keith Noll (STScI) Binary Planetesimals in Debris Disks The Solar System?s Kuiper Belt is the only debris disk where individual planetesimals in the disk can be studied directly. An understanding of the dynamical history of the Kuiper Belt provides a window into the late stages of giant planet formation and the concomitant clearing retain signatures of the younger, denser protoplanetary disk. One such signature is the remarkably high number of binary objects that have survived to the present era. The largest, high angular resolution, homogeneous survey of the Kuiper Belt carried out to date is the observation of 78 Kuiper Belt objects with NICMOS on the Hubble Space Telescope. I review our work on this sample which currently shows evidence for at least 11 binary systems for a binary rate of 14+/-4%. When recent evidence for possible contact binaries and observational incompleteness are taken into account, the true fraction of binaries could be significantly higher. Whatever the underlying fraction of binaries may prove to be, it is clear that theoretical models of disk clearing must be able to preserve a remarkably high fraction of weakly bound objects. _____________________________________________________________________ Francis O'Donovan(Caltech) and David Charbonneau(Harvard CfA) Eliminating false detections of transiting planets from two TrES fields in Andromeda and Cygnus We present some planet candidates identified with Sleuth, our automated 10 cm telescope (6 degree square FOV) located at Palomar Observatory in Southern California. We selected candidates from a new field in Andromeda (which we monitored for approximately 40 clear nights between UT 2003 August 27 and October 24) and one in Cygnus (observed for about 70 almost cloudless nights between UT 2004 June 12 and September 1). Using 2MASS colors, proper motions and multi-epoch spectral monitoring, we tried to determine the true nature of these systems, and segregate false positives from the planet candidates. Sleuth, together with STARE (located in Tenerife) and PSST (Arizona), form the Transatlantic Exoplanet Survey network of telescopes, and we have combined observations made with these three telescopes. We present long-period candidates selected from this accumulated data which were not identified from the individual data sets. By switching from weighted-aperture photometry to image subtraction based on ISIS, we have improved our photometric precision and increased the number of stars that we can monitor for transiting Jupiters. _____________________________________________________________________ Gordon I. Ogilvie, University of Cambridge Douglas N. C. Lin, University of California at Santa Cruz Tidal interactions between planets and stars The tidal interaction between a short-period planet and its host star plays an essential role in determining its spin and orbital properties. Periodic tidal forcing of a convective giant planet excites inertial waves with an intricate spatial structure, requiring high-resolution numerical calculations. Contrary to a standard assumption, the resulting dissipation rate and tidal torque depend in an erratic way on the forcing frequency. The relevant limit of very small viscosity, in which the disturbance can become localized on wave attractors, can be understood by means of an asymptotic analysis. We describe the implications of these findings for extrasolar planets and discuss the major remaining uncertainties in this theory. _____________________________________________________________________ Diane Paulson (NASA GSFC) Looking for Planets Around Nearby Young Stars The presence of stellar activity has been shown to interfere with planet detection via the radial velocity technique. The increased photospheric activity will also hinder detection of planets via the transit method. Young stars, in particular, are strongly affected, but they are a very important population of stars with regard to the understanding of the evolution of planetary and brown dwarf companions. Current extrasolar planet surveys, save recent AO surveys for wide companions, disregard the youngest stars because the signal of most planetary systems will be hidden within the noise caused by activity. In this paper, I will present the most recent findings of a radial velocity survey for short-period, high-mass substellar companions around young stars and discuss the limitations of such programs. _____________________________________________________________________ Margaret Pan (Caltech) Generalized Lagrange points: studies of resonance for very eccentric orbits A number of dynamically interesting aspects of the formation of our solar system---including, for example, the sculpting of the Kuiper belt and the creation of the Oort cloud---involve small bodies on eccentric orbits which are perturbed by a dominant major planet. Due to the sizeable eccentricities involved, these situations are hard to study using the usual eccentricity expansion of the disturbing function often applied to the restricted circular three-body problem. As an alternate approach, we develop a framework based on energy kicks for the evolution of high-eccentricity long-period orbits in the restricted circular planar three-body problem with Jacobi constant close to 3 and with secondary to primary mass ratio $\mu\ll 1$. We use this framework to explore mean-motion resonances between the test particle and the massive bodies. This approach leads to a redefinition of resonance orders for the high-eccentricity regime in which a p:p+q resonance is called `pth order' instead of the usual `qth order' to reflect the importance of interactions at periapse. This approach also produces a pendulum-like equation describing the librations of resonance orbits about fixed points which correspond to periodic trajectories in the rotating frame. A striking analogy exists between these new fixed points and the Lagrange points as well as between librations around the fixed points and the well-known tadpole and horseshoe orbits; we call the new fixed points the `generalized Lagrange points'. Finally, our approach gives a condition $a\sim \mu^{-2/5}$ for the onset of chaos at large semimajor axis $a$; a range $\mu < \sim 5\times 10^{-6}$ in secondary mass for which a test particle initially close to the secondary cannot escape from the system, at least in the planar problem; and a simple explanation for the presence of asymmetric librations in exterior 1:N resonances and the absence of these librations in other exterior resonances. _____________________________________________________________________ Francesco Pepe et al. (Obs. Geneve, Switzerland) Astrometric Survey for Extra-Solar Planets with PRIMA With PRIMA - the Phase-Referenced Micro-arscecond Astrometry facility on the Very Large Telescope Interferometer - it will be possible to measure astrometric signatures as tiny as 10 micro-arcseconds. This will allow us to follow-up many of the known extrasolar planets and determine their orbital inclination and real mass, and explore also a new parameter range of planet orbits and host stars not yet covered by radial-velocity and transit surveys. A close look at the respective detection limits reveals the perfect complementarity of all these techniques. Recently we have formed an international Consortium of astronomical institutes to set up, in collaboration with the European Southern Observatory (ESO), a project which aims at optimizing PRIMA for this goal. In the frame of this project the Consortium will deliver to ESO differential delay lines, system and error budget analysis, as well as specialized astrometry software. Our objective is to concretize, starting on 2007, the astrometric survey for extra-solar planets with this unique facility. _____________________________________________________________________ Dan Potter, Matthew C. Graham, David Sudarsky, and Laird M. Close Steward Observatory PEPPER: A High Speed Differential Photometer and Polarimeter for Planet and Debris Disk Studies A fast differential photometer has been designed to measure the minute spectral contrast phase variations (~3e-5) of short period (T~3 days) "Hot Jupiters" from the combined star+planet signal. The design uses fast ferroelectric liquid crystal (FLC) retardance modulators in conjunction with a novel polarization spectral encoding technique to calibrate atmospheric and detector gain variations faster than they can significantly change (t~1ms). The use of low noise avalanche photodiodes as the detector allows for a photon-noise limited narrow-band differential photometric accuracy of ~5e-6 for bright stars (V~6) on a 2 meter class telescope after a few hours of observing. In addition to the differential photometer, PEPPER will have a low spatial resolution polarization mode for the high contrast detection of debris disks. Here, the expected performance of the instrument in detecting the photometric signature of known short period radial velocity planets as a function of their orbital phase is presented. In addition, the system's sensitivity for the detection of the scattered light signature of debris disks around nearby, bright stars is estimated as well. _____________________________________________________________________ Lisa Prato (Lowell Observatory) New Low-Mass Spectroscopic and Visual Binaries in Ophiuchus At the 140 pc distance to the nearest star forming regions, faint, low-mass M stars present challenging targets for radial velocity surveys for spectroscopic binaries. However, the frequency and mass ratio distribution of the closest, low-mass binaries bear directly on models of star, brown dwarf, and planet formation (e.g., Bate et al. 2003). Furthermore, spectroscopic observations provide mass ratios independent of many of the assumptions needed to convert visual binary magnitude differences into mass ratios. I present the results of a survey of 34 T Tauri M stars in the Ophiuchus molecular cloud complex. Their youth was confirmed by detections of X-rays and lithium lines (Martin et al.1998). Using the NIRSPEC high-resolution, infrared spectrometer, I observed each star at 3-4 epochs over the past 2.5 years with the 10 m Keck II telescope. Five of the 34 objects are newly discovered spectroscopic binaries, two of which are located within sub-arcsecond visual binaries, yielding hierarchical triple systems. In addition, three other sub-arcsecond visual binaries were identified. Four of the spectroscopic binaries are double-lined; two have mass ratios close to unity. The single-lined spectroscopic binary has an M0/M1 primary and a small velocity amplitude, suggestive of a very low-mass, possibly substellar, secondary. Additional epochs of observation at higher signal to noise may reveal the spectral signature of this very late type companion. _____________________________________________________________________ D. Queloz, F. Pont et al., Geneva Observatory The planet found by precise radial velocity follow-up on recent candidates detected by OGLE: results and implications Measurements of the radial velocity of 60 stars with short period weak transits detected by OGLE in the direction of the Galactic-Center and Carina have been obtained for different epochs with the multi object fiber link FLAMES-UVES at the VLT. Amongst these candidates, three planetary mass objects have been confirmed and their planetary radius measured. We plan to discuss these findings and to outline the major outcomes of this large program, in particular: 1. The mass-radius relation for short planets and for object in the bottom of the main sequence 2. Statistical impact of our measurements and the lack of very-short period planet in the Doppler survey 3. Consequence on the follow-up strategy for future transits to be detected by the COROT satellite. _____________________________________________________________________ Elisa V. Quintana & J.J. Lissauer (NASA ARC) Terrestrial Planet Formation in Binary Star Systems More than half of all main sequence stars, and an even larger fraction of pre-main sequence stars, are in binary/multiple star systems. Virtually all previous models of planet formation, however, have assumed an isolated single star. Observations indirectly suggest disk material around one or both components of young binary star systems. If planets form at the right places within such disks, they can remain dynamically stable for very long times. We are simulating the late stages of growth of terrestrial planets within binary star systems, using two new symplectic integrators that we have developed for this purpose. We show that the late stages of terrestrial planet formation can indeed take place in a wide variety of binary systems, and we have begun to delineate the range of parameter space for which this statement is true. Simulations of accretion in the $\alpha$ Centauri AB binary system show that terrestrial planets similar to those in the Solar System may have formed around $\alpha$ Cen A and/or $\alpha$ Cen B provided that an accretion disk began at a low inclination ($\lesssim$ 30$^{\circ}$) relative to the stellar orbit. Terrestrial planets may also form around close--binary stars with stellar apastron distances (the largest separation of the stars) $Q_B$ $\lesssim$ 0.4 AU, which includes $\sim$ 10\% of all main-sequence binary systems. Terrestrial planets may also form around one component of a wide--binary system if the stellar periastron (the closest approach of the stars) $q_B$ $\gsim$ 7 AU, and approximately 50\% of binary systems fall within this range. Given that the galaxy contains more than 100 billion star systems, and that $\sim$ 60\% remain viable for the formation and maintenence of Earth-like planets, a large number of systems remain potentially habitable based on the dynamic considerations of this research. _____________________________________________________________________ F.A. Rasio (Northwestern), E.B. Ford (Berkeley), and V. Lystad (Northwestern) Evidence for Planet-Planet Scattering in Upsilon Andromedae We analyze the system of three planets around Upsilon Andromedae. We show that the orbital configuration of the outer two planets can only be explained if the planets started on nearly circular orbits and the outer planet was perturbed suddenly into a high eccentricity state. The eccentricity of the middle planet oscillates on secular time scales, periodically returning to its initial low value. The impulsive perturbation to the outer planet arises naturally from a close dynamical interaction with another planet, now lost from the system. This provides strong evidence that planet-planet scattering causes the high eccentricities of at least some extrasolar planets. _____________________________________________________________________ Sean Raymond (U Washington), Tom Quinn (U Washington), and Jonathan Lunine (U Arizona) Can habitable terrestrial planets co-exist with hot/warm Jupiters? 'Hot' or 'warm jupiters,' giant planets with orbits very close to their parent stars, are thought to form at large orbital distances and then migrate inward via interactions with the gaseous protoplanetary disk. If a giant planet forms and migrates inward with sufficient rapidity, then terrestrial planets may form in the system. We present results of simulations of terrestrial planet formation in the presence of hot/warm jupiters, broadly defined as having orbital radii within 0.5 AU of the parent star. We show that terrestrial planets similar to those in the Solar System can form around stars with hot/warm jupiters, and can have water contents equal to or higher than the Earth's. For small orbital radii of hot jupiters (e.g. 0.15, 0.25 AU) potentially habitable planets can form, but for semi-major axes of 0.5 AU or greater their formation is suppressed. We show that the presence of a giant planet external to the terrestrial planet zone does not necessarily enhance the water content of the terrestrial planets, but does descrease both their formation and water delivery timescales. We speculate that asteroid belts may exist interior to the terrestrial planets in systems with hot/warm jupiters. Sean Raymond and Rory Barnes Packed Planetary Systems II: testing for unseen massive planets in known extra-solar planetary systems Recent results have shown that many of the known extrasolar planetary systems contain regions which are stable for massless test particles. We present results of 1000+ simulations which examine the possibility that Saturn-mass planets exist in HD37124, HD38529, 55Cnc, and HD74156, just below the detection threshold, and attempt to predict likely orbital parameters for such unseen planets. Several maxima of the survival rate of test planets are located in the habitable zones of their parent stars and are therefore of astrobiological interest. We suggest the possibility that companions may lie in these locations of parameter space, and encourage further observational investigation of these systems. We also present results of simulations of late-stage accretion of terrestrial planets in these systems. _____________________________________________________________________ William (Ken) Rice (Natal, South Africa) Grain growth in self-gravitating protoplanetary disks. The role of disk self-gravity in the formation of gaseous planets is still uncertain. Although the idea that gaseous planets could form directly through a disk instability is attractive, it does have a number of problems. It requires fairly massive disks, extremely efficient cooling, and if it does work, may only produce massive planets. It is, however, quite likely that protoplanetary disks experience a self-gravitating phase, even if this does not lead to disk fragmentation. We present, here, simulations of embedded particles in self-gravitating protoplanetary disks. The results of these simulations suggest that particles that would normally experience rapid inward migration become concentrated in the centers of the self-gravitating spiral structures. This leads to a significant increase in their collision rate which should accelerate grain growth. The densities achieved may also be sufficiently high for the dust itself to become self-gravitating. It seems, therefore, that even if gravitational instabilities cannot form gas giant planets directly, they may play an important role in accelerating the grain growth required for the formation of planetary cores. _____________________________________________________________________ L.J. Richardson (1), S. Seager (2), D. Deming (1), R.K. Barry (1), J. Rajagopal (1), D. Wallace (1), and W.C. Danchi (1) (1) NASA Goddard Space Flight Center (2) Carnegie Institution of Washington Theoretical Infrared Light Curves and the Detectability of Close-In Extrasolar Giant Planets We have developed a spectral synthesis routine to calculate theoretical spectra of extrasolar giant planets from 3 to 24 microns. The code requires a temperature-pressure profile as input, calculated by solving the radiative transfer equation; it then calculates continuum opacities and line opacities for water, carbon monoxide, and methane, and integrates over the layers of the atmosphere to determine the emergent flux density. We have integrated this code with another routine that computes the orbital parameters for a general non-circular orbit and integrates over the disk to determine the total flux as a function of orbital phase. We assume a temperature asymmetry between the day and night sides, since the planet is likely to be tidally locked. The result is a set of multi-wavelength, infrared light curves that predict the detectability of known extrasolar planets, and in particular, what temperature asymmetry would be observable. We consider several space-based instruments, such as the Fourier-Kelvin Stellar Interferometer (FKSI), JWST, and Spitzer; by integrating the theoretical spectrum over the bandpass of a particular instrument, we compute theoretical light curves for known extrasolar planets. _____________________________________________________________________ Matthew J. Richter (UCD) TEXES Observations of Pure Rotational H2 Emission from T Tau Pure rotational H2 emission is a potentially powerful diagnostic of gas in protoplanetary disks. Three transitions are available from ground-based observatories: J=3-1 at 17 microns, J=4-2 at 12 microns, and J=6-4 at 8 microns. The energies of the levels involved result in sensitivity to gas with temperatures in the range 150-800 K. With sufficient spectral resolution, it should be possible to analyze line profiles in an attempt to determine gas temperature as a function of velocity and, in the case of Keplerian disk rotation, radius. We present observations of T Tau using TEXES, the Texas Echelon-cross-Echelle Spectrograph, at the IRTF. We have resolved line profiles for each of the three mid-infrared transitions and find there are two distinct velocity components. We will discuss our observations and their interpretation at the meeting. _____________________________________________________________________ Aki Roberge (Carnegie), Alycia J. Weinberger (Carnegie), Paul D. Feldman (Hopkins), & Seth Redfield (U Texas) Limits on Primordial Gas in the AU Microscopii Disk from Far-UV Spectroscopy AU Mic (GJ 803) recently became the first debris disk imaged around an M-type star (Kalas, Liu, & Matthews 2004). It is a member of the Beta Pictoris moving group, indicating it is about 12 Myr old (Zuckerman et al. 2001). This disk is extraordinarily well-suited for comparison to the well-studied Beta Pic debris disk and provides a unique opportunity to examine the dependence of protoplanetary disk evolution on spectral type. The low inclination of the AU Mic disk permits investigation of the disk gas with line-of-sight absorption spectroscopy, as has been done in the case of Beta Pic. In particular, far-UV absorption spectroscopy is sensitive to small amounts of cold molecular hydrogen (H2) gas, the primary constituent of gas giant planets. We present a firm upper limit on H2 in the disk using the Far Ultraviolet Spectroscopic Explorer satellite. This limit is much lower than that obtained from non-detection of mm-wavelength CO emission, and does not require extrapolation from an assumed CO/H2 ratio (Liu et al. 2004). In addition, there is a hint of H2 absorption at a column density an order of magnitude or more below our upper limit. If confirmed, this would be the first detection of H2 in a debris disk (previous claims of H2 in debris disks using IR emission spectroscopy have been discredited; Thi et al. 2001, Richter et al. 2002, Chen et al. 2004). The upper limit on H2 relative to the dust in the AU Mic disk clearly shows that the primordial gas has been largely depleted, although some of the dust may be primordial. The gas depletion timescale was probably not very different in the AU Mic and Beta Pic protoplanetary disks, despite their very different stellar masses (AU Mic mass = 0.5 solar masses, Beta Pic mass = 1.8 solar masses). This fact should provide strong constraints on the gas depletion mechanism. It also has consequences for the theory of giant planet formation around low-mass stars, since the timescale for giant planet formation through core-accretion increases with decreasing stellar mass (Laughlin et al. 2004). Kailash Sahu, STScI Ronald Gilliland, STScI Howard Bond, STScI Tim Brown, HAO Stefano Casertano, STScI Mario Livio, STScI Dante Minniti, U. Catolica Nino Panagia, ESA/STScI Alvio Renzini, ESO Michael Rich, UCLA Ed Smith, STScI Manuela Zoccali, U. Catolica Search for Planets around Stars towards the Galactic Bulge Using HST Using HST, we have monitored a Galactic Bulge field over a continuous 7-day interval (2004 Feb 23-29) in order to detect transits by orbiting Jovian planets. We have photometrically monitored 120,000 F, G, and K dwarfs, and we are now in the final stages of the data-analysis. This program should lead to robust detection several dozen transiting planets. For the brighter candidates with transits, we have also carried out radial-velocity measurements using the 8-m VLT, in order to confirm the planetary nature of the companions. The metallicities of the target stars range over more than 1.5 dex, allowing for a determination of the dependence of planet frequency upon metallicity--a crucial element in understanding planet formation. We also expect to determine the distribution of planetary radii for a large sample of extrasolar planets. I will present some first results of our program at this conference. _____________________________________________________________________ Nuno Santos (Lisboa, Portugal) Stellar metallicity and the probability of planet formation Planet host stars are known to have an average metal content significantly above the one found in stars without detected planetary companions (Gonzalez 1998; Santos et al. 2001). Furthermore, it has been shown that the frequency of giant planets steeply increases with the stellar metallicity (Santos et al. 2001,2004; Reid 2002). This suggests that the efficiency of giant planet formation is an increasing function of the grain content of the proto-planetary disk. In this talk we will focus on the most recent results about the chemical abundances of planet-host stars, and discuss the constraints they are bringing to the theories of planet formation and evolution. Abundances of iron-peak, alpha-elements, and of the light elements Li and Be will be presented, and a few interesting and unexpected trends will be discussed. _____________________________________________________________________ Bun'ei Sato (Kobe University, Japan) Okayama Planet Search Program: Search for Planets around G-type Giants We have carried out a precise Doppler survey of G-type giants aiming to unveil the properties of planets around intermediate-mass stars (1.5-5M). G-type giants are slow-rotators and have many sharp lines in their spectra and their surface activities are relatively low in contrast to their younger counterparts on the main-sequence, which allow us to detect giant planets around them by precise radial velocity measurements. We are now monitoring about 300 late-G giants (including early-K giants) using HIgh Dispersion Echelle Spectrograph (HIDES) equipped with an iodine absorption cell at Okayama Astrophysical Observatory in Japan. Up to now, we have succeeded in discovering the first extrasolar planet around a G-type giant star HD 104985, and also found several stars showing significant radial velocity trends, suggesting the existence of stellar and substellar companions. We here report the newly discovered planetary candidates and the results of our survey obtained in these three years. Future prospects are also discussed. _____________________________________________________________________ Re'em Sari (Caltech) The Formation of The Solar System We describe a scenario for the formation of planets in our solar system. It features fast formation of the outer planets, and explains the masses of the planets, their spacing and their circular orbits. We suggest that the available mass was just that of the minimum mass solar nebula for the inner solar system and a few times more in the outer solar system. We give predictions for the size distribution of objects in the Oort cloud and for the life time and properties of debris disks around young stars. _____________________________________________________________________ E. Serabyn (NASA JPL), P. Haguenauer (ESO, Chile), E. Bloemhof (California Institute of Technology ), K. Wallace (JPL), M. Troy (JPL) and C. Koresko (JPL) High contrast imaging near bright stars with an off-axis phase-mask coronagraph A novel off-axis coronagraph is being developed for deployment on a large ground-based telescope, in order to search for faint, close-in companions to nearby stars. Our coronagraphic system consists of a near-infrared four-quadrant phase mask (FQPM) coronagraph coupled to an off-axis section of a large telescope. The combination of this type of coronagraph with a well-corrected off-axis telescope provides three advantages: 1) high on-axis starlight rejection by the phase mask, 2) a completely unobscured aperture, thus eliminating several sources of diffracted starlight, and 3) a much improved adaptive optics wavefront correction, due to the reimaging of the smaller off-axis pupil onto an existing deformable mirror. The combination of these three factors (as well as the use of infrared wavelengths) should enable very high starlight rejection, making possible the search for faint companions at small angular separations from bright stars. An infrared FQPM coronagraph has now been successfully tested at JPL, and the full system will be tested on the sky this summer at Palomar. _____________________________________________________________________ Steinn Sigurdsson (Penn State) TBD _____________________________________________________________________ Ian Skillen, D. Pollacco, D.J. Christian, W.I. Clarkson, A. Collier Cameron, N.A. Evans, A. Fitzsimmons, C.A. Haswell, C. Hellier, S.T. Hodgkin, K. Horne, J. Irwin, S.R. Kane, F.P. Keenan, T.A. Lister, A.J. Norton, J.P. Osborne, R. Ryans, R.A. Street, R.G. West, P.J. Wheatley. Current Status of the WASP Project The UK Wide Angle Search for Planets (WASP) is a robotic, ultra wide-angle photometric survey of bright stars in the magnitude range ~7-15, with the primary science goal of detecting hot-Jupiter exoplanet transits. The SuperWASP-I station was constructed at the ORM, La Palma in the Fall of 2003, and started routine observations in April 2004. Construction of a clone station, SuperWASP-II, in the southern hemisphere at the Sutherland site of the SAAO, is planned to start in 2005. The SuperWASP-I facility consists of an array of cameras mounted on a fast-slew fork mount, housed in a reinforced fibre-glass enclosure. Each camera, comprising a Canon 200mm f/1.8 lens and a passively-cooled 2Kx2K thinned EEV science-grade CCD detector, has a field-of-view of 7.8 x 7.8 degrees and a plate scale of 14 arcsec/pixel. An integrated weather station provides monitoring of local weather conditions, and robotic operation of the enclosure slide-away roof and fork mount, and data acquisition, is controlled using Linux-based computers. From April to October 2004 SuperWASP-I operated with 5 cameras, giving sky coverage of ~300 square degrees per pointing. Operational reliability proved to be extremely high throughout this period in which monitoring observations were made of 21 fields located out of the galactic plane. This ~4 TB dataset will yield time-series photometry with a precision of better than ~1% for more than one million stars brighter than 13th magnitude. In this paper we discuss the SuperWASP-I hardware and data acquisition infrastructure, and present plans for a substantial upgrade to the facility. _____________________________________________________________________ Insoek Song, Gemini Observatory Northern Operations Center An Amazingly Dusty Sun-like Star: Cosmic Collisions at 1 AU The has been attributed in almost all cases to cold dust particles in disks orbiting 50-100 AU from the central star. These disks appear to be analogous to the Kuiper Belt of comets in our solar system. By contrast, warm, dusty regions analogous to the Sunat other main sequence stars. Here we report extraordinary mid-IR excess emission from a solar-type star of estimated age a few hundred million years. The region in the vicinity of 1 AU from this star is about one million times dustier than the zodiacal dust cloud of our solar system. In addition, based on its mid-IR spectrum, the typical dust particles in this star appear to be of micron size which is much smaller than typical zodiacal dust particles. Survival times of micron-size grains ~1 AU from the central star are typically only a few 1000 years. So, the extraordinary quantity of dust may only be explainable by frequent and/or huge collisions between asteroids or other zetti A Keck/HIRES Search for Planets Orbiting Metal-Poor Dwarfs The distributions of planet masses and orbital elements, different correlations among them, and measurable differences in planetary frequency are likely to be generated by diverse planetary formation scenarios and evolution mechanisms as well as different formation and evolutionary histories of the parent stars (binarity, spectral type, metallicity, age). We present results from our ongoing spectroscopic search for giant planets within 1 AU around a well-defined sample of metal-poor stars with HIRES on the Keck 1 telescope. We have achieved an rms radial velocity precision of 8 m/s over a time-span of 2 years. The data collected so far build toward evidence of the absence of very short-period (< 1 month) giant planets. However, about 7% of the stars in our sample exhibit velocity trends indicative of the existence of companions. We place preliminary upper limits on the detectable companion mass as a function of orbital period, and compare them with the performance of future space-borne high-precision astrometric observatories. Our findings will help to confirm or disprove the existence of a correlation between the orbital periods of extrasolar planets and the metallicity of the host stars and to refine our overall understanding of the dependence of planetary frequency on stellar metallicity. _____________________________________________________________________ K. Stapelfeldt (JPL), V. G. Ford (JPL), K. Balasubramanian (JPL), D. Content (NASA/GSFC), P. D. Lisman (JPL), S. Shaklan (JPL), J. Trauger (JPL) Status of Terrestrial Planet Finder Coronagraph The Terrestrial Planet Finder Coronagraph (TPF-C) technology development and mission architecture is progressing to enable a launch date in 2015 timeframe. The status of the technology effort in areas related to achieving deeper starlight suppression and the mission architecture development, design choices and challenges will be summarized in this poster. The technology summary will include recent test results from the High Contrast Imaging Testbed; status of the Technology Demonstration Mirror; investigation results of coating analyses; and masks and stops theory, modeling and fabrication progress. System architecture progress will include trade studies on primary mirror, telescope form, orbit, structural choices, and thermal control. Performance of the first iteration of the system will be presented as well as direction toward the next baseline being evaluated. K. Stapelfeldt, M. Werner, C. Beichman, G. Bryden (JPL) K. Su, G. Rieke, J. Stansberry, D. Trilling, MIPS instrument team (U of A) T. Megeath, M. Marengo (CfA) C. Chen (NOAO) M. Jura (UCLA) D. Watson (Rochester) D. Hines (SSI) J. Van Cleve (Ball) Debris disks resolved with Spitzer We report on Spitzer imaging and spectroscopy of nearby, spatially resolved debris disks. These observations reveal new details of the disk dust distribution, the dust particle properties, and limits on companions to the sytems. The far-infrared emission from the Vega disk appears to be dominated by small particles being blown out of the system. The Fomalhaut and eps Eri disks, which appear as rings in submillimeter maps, have their central regions filled in by warm dust in the MIPS images. A prominent asymmetry in the Fomalhaut disk may indicate dynamical perturbations from an unseen planet. Only beta Pictoris shows strong evidence for solid-state grain spectral features. The results of these studies will lay the foundation for understanding the multitude of additional debris disks that Spitzer is detecting photometrically. _____________________________________________________________________ Jason Steffen, University of Washington Detecting Terrestrial Planets in Transiting Systems I present our initial investigation into a new planet detection technique that uses the timing of planetary transits. The transits of a solitary planet orbiting a star occur at equally spaced intervals in time. If a second planet is present, dynamical interactions within the system will cause the time interval between transits to vary. These transit time variations can be used to infer the orbital elements of the unseen, perturbing planet. I show analytic expressions for the amplitude of the transit time variations in several limiting cases such as: low eccentricity orbits, non-interacting planets, mean-motion resonances, etc. Under certain conditions the transit time variations can be comparable to the period of the transiting planet and, as is the case in some mean-motion resonances, they can be independent of the mass of the perturbing planet. I also give numerical calculations of the time variations that would occur in several known multi-planet systems if they were transiting. In roughly half of these systems the RMS time deviations are larger than one hour---a signal easily detectable with ground-based observations. Transit timing variation shows promise as a planet detection technique as it should be capable of detecting Earth-mass planets around sun-like stars with existing observational equipment. _____________________________________________________________________ Rachel Street, APS Division, Dept. of Physics, Queen's University Contributed on behalf of the WASP Consortium. (In alphabetical order) D.J. Christian, W.I. Clarkson, A. Collier Cameron, N.A. Evans, A. Fitzsimmons, C.A. Haswell, C. Hellier, S.T. Hodgkin, Keith Horne, S.R. Kane, F.P. Keenan, T.A. Lister, A.J. Norton, D. Pollacco, R. Ryans, I. Skillen, R.A. Street, R.G. West, P.J. Wheatley. First Results from SuperWASP-I (La Palma) Since SuperWASP-I formally began science operations in April 2004 we have obtained ~4TB of time-series data on ~2.7 million stars between V~7-14.5mag. The primary science goal of the Consortium is to use these data to hunt for exoplanetary transits, but the ultra-wide angle fields of view (7.8deg x 7.8deg per camera) leads to challenging complications in the data reduction process. Our Consortium has developed customised data redution pipeline and analysis software to deal with these issues. Here we present a description of the pipeline, transit-detection algorithm and our first results. This instrument was built and is operated by the WASP Consortium, consisting of astronomers from Cambridge University, the Instituto de Astrofisica de Canarias, the Isaac Newton Group, Keele University, Leicester University, Open University, Queen's University Belfast, and St. Andrews University. _____________________________________________________________________ Guy Stringfellow (U Colorado) The Current Status of the Eruptive Young Stellar Object V1647 Ori V1647 Ori is a young stellar object that recently emerged from a dark cloud. Within the last year it experienced what is believed to be an accretion driven outburst of the EXor/FUor type, triggered within the circumstellar disk. Since discovery we have been following the optical and infrared outburst from various ground-based observatories. Our program intends to follow the outburst through its return to quiescence, thereby characterizing the nature of the outburst and the response of the circumstellar environment. The underlying star is expected to be a Classical T Tauri star, and the circumstellar disk the potential progenitor site of planet formation. Understanding the origin of such energetic outbursts and the influence on the circumstellar environment could provide important insight into how, when, and where planets may or may not form around low-mass stars. We will provide a current update on the outburst of this intriguing system. _____________________________________________________________________ Micaela Stumpf (MPIA in Heidelberg, Germany) Search for planetary-mass companions to young brown dwarfs in the solar neighbourhood We present the first results of the search for planetary-mass companions to young brown dwarfs with the new direct detection technique of spectral differential imaging. The data we use were obtained with the Hubble Space Telescope (HST/NICMOS) in two narrow-band filters, one places in (1.082 micron) and one off (1.13 micron) but nearby the molecular bands, taken at the same time. The advantage of this technique is the fact that a giant planet shows a molecular (H2O) absorption band at about 1.10 micron where the continuum flux drops significantly. Therefore subtraction of the two narrow-band images will cancel out any primary without strong spectral features while the flux of a planet companion is still visible. Since any planetary-mass companion to an old brown dwarf is relatively cool and low of luminosity, we focused on young objects (< 1Gyr) in the solar neighbourhood (< 30pc). As targets we chose 12 young isolated (with no known close companion so far) L-dwarfs which still show Lithium in their atmosphere. With these assumptions, a planetary-mass companion with a mass > 6 Jupiter masses and a separation larger than 3 AU should be bright enough for a direct detection. _____________________________________________________________________ Genya Tadeka and Fred Rasio (Northwestern) Structure and Evolution of Nearby Stars with Planets Using the YALE stellar evolution code, we are creating theoretical main-sequence and post main-sequence stellar evolution models to study the physical properties of planet-host stars. Detailed structure and evolution models of host stars are essential in understanding the extrasolar planets and setting the constraints on their dynamics and formation theories. Our purpose is to construct a database with a complete set of theoretical stellar evolution tracks that will be widely availed to calculate various physical parameters of stars. The database covers a range in mass 0.5M_sun < M < 1.5M_sun, and in metallicity -1 < [Fe/H] 0.5. Observable parameters (luminosity, effective temperature and metallicity) with uncertainties are taken as input parameters to estimate the probability distributions of various output model parameters (mass, age, radius, size of convective envelope, etc.). We have adopted Bayesian probability theory to give a robust estimation of the posterior probability functions of desired model parameters and correct for potential systematic biases induced by local non-linearity of stellar evolution tracks. We construct various stellar models with most recent spectroscopic and parallax data to discuss specific systems in the context of planet formation theory and orbital dynamics. _____________________________________________________________________ Yuske Taguchi (Kobe, Japan) The Metallicity of T Tauri Stars We here present the analysis, and newly developed method of determining the fundamental atmospheric parameters: effective temperature Teff; surface gravity log g; microturbulence (xi)mt; metallicity [Fe/H]; of T Tauri stars. We have conducted high- resolution spectroscopic observations of a sample of both Classical and Weak-line T Tauri stars embedded in the Taurus Molecular Cloud. Using the ratios of equivalent widths or flux of specific lines, we have efficiently eliminated the effects of "veiling" and determined the atmospheric parameters individually for each object. We will introduce in detail the method of determination and results for each parameter, and discuss possible improvements and the accuracy of this method for use in future work. _____________________________________________________________________ Angelle Tanner (NASA JPL) and Charles Beichman (Caltech) Companion Search Around SIM/YSO Targets with Palomar AO+Coronagraph Observations Over the past year we have observed a sample of nearby T-Tauri stars with the Palomar PALAO/PHARO+Coronagraph in an effort to identify stellar or planetary companions which would affect the star's viability as a SIM target. Our sample consists of 40 stars in the Pleiades and Taurus-Aurigae clusters. We are looking within a range of 50 to 1000 AU with the potential of detecting planets down to 10-20MJ. Thus far, we had detected 8 potential companions around 5 stars in the Pleiades and 23 potential companions around 14 stars in Taurus. Follow up observations including AO imaging and spectroscopy will be conducted in the next year to prove whether these sources are true companions. _____________________________________________________________________ Stuart F. Taylor, William G. Bagnuolo, Harold A. McAlister, Theo ten Brummelaar, L. Sturmann, J. Sturmann, N. H. Turner, D. Berger (Georgia State University), S. T. Ridgway (KPNO, NOAO), Center for High Angular Resolution Astronomy (CHARA) Collaboration Separated Fringe Packet Binaries Individually resolved packets are produced by scans from the CHARA Interferometer Array for binary stars with separations from 10 to 100 milli-arcsec (mas) in the K' band. We have used this Separated Fringe Packet Binary (SFPB) data for astrometry of the binary with the goal of improving the visual orbits for these systems. About 12 data sets of 400 scans each can be collected for a star within an hour. The intrinsic accuracy with simple linear/quadratic fits to the time-separation curve yields accuracies of 0.15 mas. But, for systems with separations less than 80 mas, the measured separation is modulated periodically by the secondary star's packet riding over the sidelobes of the primary which provides a phase reference. This "sidelobe verniering" can improve the precision to better than 50 micro-arcsec. These techniques represent 1-2 orders of magnitude improvement in astrometic accuracy over speckle interferometry techniques. Visual orbits can then be refined via a maximum likelihood technique, which leads to revisions in the stellar masses. We are currently collecting data on SFPBs which have know "third companions," to detect the perturbation on the large orbit by the third body. This technique will allow the CHARA Array to look for companions to SFPB-type binaries in the exoplanet mass range. We present the results for several binaries that have been observed at the CHARA Array, starting in 2001. _____________________________________________________________________ Ed Thommes (CITA, University of Toronto) A safety net for fast migrators: Interactions between Type I and Type II bodies in a protoplanetary disk Young planets interact with their parent gas disk through tidal torques. An imbalance between inner and outer torques causes bodies the mass of gas giant solid cores, $\sim 10 M_\oplus$, to undergo orbital decay on a timescale generally shorter than their formation time (``Type I" migration). This makes the first stage of giant planet formation problematic; however, bodies which do manage to reach gas giant size, O($10^2 M_\oplus)$, open a gap in the disk and subsequently migrate more slowly, locked into the disk's viscous evolution (``Type II" migration). In a young planetary system, both types of bodies likely coexist. If so, differential migration will result in close encounters between them. We numerically investigate the resulting dynamics, and find, as has been previously suggested, that sub-gap-opening bodies have a high likelihood of being resonantly captured when they encounter a gap-opening body. A gas giant planet thus tends to act as a barrier in a protoplanetary disk, stopping smaller, faster-migrating protoplanets outside of its orbit. In this way, a gas giant planet may facilitate the formation and survival of subsequent planets---in particular, the next gas giant's core. _____________________________________________________________________ Henry Throop (SWRI) and John Bally (U. Colorado / CASA) Planetary Formation near Dense Clusters : Hazardous or Not? Most models of planet formation assume that the Sun formed in isolation, where it was not influenced by the effects of other stars. However, a growing body of observations suggest that the vast majority of solar-type stars form in OB associations such as Orion. Intense UV radiation from the cores of these clusters rapidly can destroy circumstellar disks surrounding low-mass stars on sub-Myr timescales, making planetary formation difficult. However, the loss of gas from these disks may actually contribute to the rapid formation of planetesimals in these disks, by allowing gravitational instabilities of midplane dust to grow large bodies. Furthermore, it is possible that UV photolysis of ices in these disks may provide a net increase in the amount of complex organic molecules available for pre-biotic processes. Therefore, instead of being a hazardous environment, star birth in a dense cluster may in some circumstances encourage the formation of habitable planets. _____________________________________________________________________ V. Tolls (Harvard CfA), P. Nisenson (Harvard CfA), M.J. Aziz (Harvard), R.A. Gonsalves (Tufts University), S.G. Korzennik (Harvard CfA), A. Labeyrie (Observatoire de Haute-Provence), R.G. Lyon (GSFC), G.J. Melnick (Harvard CfA), and R.A. Woodruff (Lockheed-Martin Corp.) Study of Coronagraphic Techniques Direct imaging of extra-solar planets is important for determining the properties of individual planets and to study multi-planet systems. Obtaining spectra of extra-solar planets enables us to constrain the composition of planetary atmospheres and surfaces, their climates, and their rotation periods. The techniques required to isolate and detect an extra-solar planet next to its host star are quite challenging and require significant improvement. SAO is setting up a testbed to study coronagraphic techniques, starting with Labeyrie's multi-step speckle reduction technique. This technique incorporates a speckle phase corrector and second occulter for speckle light suppression. The goal is to study this technique in the testbed for its application in coronagraphic cameras. In addition, the testbed will be used to characterize soft-edge occulters. Simulations of soft-edge occulters with a Gaussian absorption profile show a promising reduction of the flux in the core of the point spread function in coronagraphs. We expect this to lead to a reduction in the inner working distance and to an increase in contrast ratio compared to a Lyot coronagraph. The occulters for the tests will be developed in Harvard's Department of Engineering and Applied Sciences and by Lockheed-Martin Corp. This poster will present the setup of SAO's testbed, simulations for all developments, and first test results. _____________________________________________________________________ Guillermo Torres, G. Mandushev, D. W. Latham, D. Charbonneau, R. Alonso, R. J. White, R. P. Stefanik, E. W. Dunham, T. M. Brown, and F. T. O'Donovan (CfA, Lowell, Caltech, IAC, HAO) The Challenge of Wide-Field Transit Surveys: False Positive Rejection Wide-field searches for transiting extra-solar giant planets face the difficult challenge of separating true transit events from the numerous false positives caused by isolated or blended eclipsing binary systems. We describe the investigation of GSC 01944-02289, a very promising candidate for a transiting brown dwarf detected by TrES, the Transatlantic Exoplanet Survey network. The photometry and radial velocity observations initially suggested that the candidate was an object of substellar mass in a 3.35-day orbit around an F star. However, careful analysis revealed subtle changes in the spectral line profiles consistent with the presence of another star in the system. Detailed modeling of the light curve and of the spectra allowed us to explain the observations as due to a "blend", composed of an eclipsing binary (G0V + M3V) plus a third star (the main F5 object) diluting the eclipses. The system is a hierarchical triple, and the F star is slightly evolved. We present some highlights of our modeling techniques. This investigation serves as an illustration of the care required to rule out astrophysical false positives in transit surveys. _____________________________________________________________________ Wes Traub (Harvard CfA) TBD _____________________________________________________________________ John Trauger and the Eclipse proposal team A case study in high contrast coronagraphs for planet discovery: the Eclipse concept and supporting laboratory experience Eclipse is a proposed Discovery mission for direct imaging of planetary systems orbiting nearby stars. The concept is an actively-corrected coronagraphic space telescope designed for high-contrast visible wavelength imaging and spectrophotometry. Predictions indicate that Eclipse imagery suppresses diffracted and scattered starlight in the field of view between 0.25 and 1.5 arcseconds from the star by at least three orders of magnitude compared to any HST instrument. Contrast predictions are derived from computational models and tested by laboratory experience. We review recent laboratory experience with high contrast imaging and developments in the enabling technologies, including apodized coronagraphic masks, precision deformable mirrors, and wavefront sensing and control algorithms. The Eclipse mission offers pioneering science observations and an opportunity to validate critical technologies in support of coronagraphic concepts for NASA's Terrestrial Planet Finder (TPF). A baseline three-year science mission could provide a survey of the nearby stars accessible to TPF, promising fundamental new insights into the nature and evolution of diverse planetary systems associated with our Sun's nearest neighbors. _____________________________________________________________________ Stephane Udry et al. (Obs. Geneve, Switzerland) Metallicity-biased extrasolar-planet search with Elodie at OHP As demonstrated by Santos et al. (2001), the occurrence frequency of exoplanets is a strongly rising function of the host-star metallicty, as soon as the metal content exceeds the solar value. In this contribution we will present the first-year results of an on-going planet-search programme with ELODIE at the Observatoire de Haute-Provence targeting metal-rich stars. The goal is to rapidly unveil new hot-Jupiter candidates and subsequently search for potential photometric transits in front of those bright stars. _____________________________________________________________________ Seitaro Urakawa, Kobe University Extrasolar Planet Search by Transit Method using the Subaru Telescope Over 130 extrasolar planets have been discovered since 1995. The discovery of extrasolar planets lead us to new understanding of planetary systems. We tried to detect extrasolar planets by transit method using Subaru Telescope (Suprime-Cam). The number of detected stars is over 25000 and their photometric accuracy is within 3%. These values strongly indicate that the Suprime-Cam is an excellent detector to search for extrasolar planets. In addition, we detected some variable stars and one extrasolar planet candidate. The decrease of flux of this candidate occurred just once during the observation run. However, the light curve has a short flat-bottomed shape, a flux depth of 2.8%, and a total duration time of about 96 minutes. It is worth noting these results are consistent with those of typical extrasolar planets. In addition, our multi-band photometry suggests the primary star is a late G-early K dwarf. Knowing this, we estimated the size of this candidate as 1.4-1.5 Jupiter radius. _____________________________________________________________________ Diana Valencia (Harvard) Scaling and Internal Structure of Masive Terrestrial Planets: Super-Earths and Super-Mercuries Recent astronomical discoveries have pointed out that planets orbiting other stars have diverse properties in mass and orbital parameters. Astronomers have recognized the likelihood of detection of extrasolar terrestrial planets and two missions (Kepler and Terrestrial Planet Finder) have been directed to the detection of these planets. Kepler mission has been scheduled to launch in 2006 and has the capability of finding rocky planets by the transit method. The first planets most likely to be discovered are the more massive ones with very tight orbits (ie. presumably very hot surfaces) around their parent start. The focus of this study is to calculate the internal structure of massive terrestrial planets starting from the knowledge acquired on the Earth and other solar system planets. With the use of equations of state for the Earth and physical laws we obtain radial structure profiles of mass, pressure and density, including all major phase changes for massive Earth-like planets. Scaling laws for the total radius, core radius, average density as a function of mass are obtained for different surface temperatures and core-mass fractions. _____________________________________________________________________ Kaspar von Braun (Carnegie / DTM) EXPLORE/OC: Photometry Results of Monitoring the Open Cluster NGC 2660 for Planetary Transits The EXPLORE/OC Project is a photometric monitoring survey of Galactic southern open clusters (OCs) with the aim to find transiting close-in extrasolar giant planets. A by-product of this search is the discovery of a wide range of different variable stars. Our search for planets in the open cluster NGC 2660 has produced several tens of variables in the field of the OC. In this presentation, we briefly outline motivations and challenges involved in such as survey, illustrate some of our methods, and show the light curves of the variable stars, their locations in the field and color-magnitude diagram of the cluster. _____________________________________________________________________ Jeff Valenti (STScI) and Debra Fischer (SFSU) Relationship between Stellar Metallicity and Extrasolar Planets Based on detailed spectroscopic analysis of over 1000 F, G, and K stars in Keck, AAT, and Lick planet search programs, we find that the probability of detecting giant planets with periods less than 4 years and velocity amplitudes greater than 30 m/s increases as the square of the iron abundance, rising smoothly from 5% at [Fe/H]=0.0 to 20% at [Fe/H]=0.3. Our uniform spectroscopic analysis of the entire sample, including all stars without planets, is the best way to characterize and remove metallicity biases in the sample. By examining metallicity distributions of stars with and without planets as a function of stellar convection zone mass and planetary orbital properties, we conclude that high metallicity enhances giant planet formation or detectability (via migration into the detection zone). We find no evidence that stars with giant planets have higher metallicity because they have accreted material rich in metals. _____________________________________________________________________ Ted von Hippel (U Texas), Marc Kuchner (Princeton), Bill Reach (California Institute of Technology), Fergal Mullally (U Texas), D. E. Winget (U Texas), Adam Burrows (U Arizona), Mukremin Kilic (U Texas) A Spitzer Search for Planets and Disks around White Dwarfs We report on our on-going Spitzer Space Telescope survey of 130 nearby white dwarfs. Our survey is sensitive to excess infrared emission at 4 and 8 microns from orbiting dust or faint companions down to an effective temperature of approximately 350 K. A detection of a 1 to 15 Jupiter-mass planet orbiting a white dwarf could mark the first direct detection of light emitted by an extrasolar planet. Though such a detection would not probe a close analog of the Solar System, it would open a new window into the investigation of the end states of planetary systems and offer the first opportunity to study the thermal spectrum of an extrasolar planet. Understanding the thermal spectra of extrasolar planets and brown dwarfs will be critical to future planet detection schemes and to understanding the origin and evolution of planetary systems. Ted von Hippel, Fergal Mullally, D.E. Winget, S. O. Kepler Searching for Planets around Pulsating White Dwarf Stars We present a new method for searching for planets around white dwarf stars, with a different sensitivity to other methods, using the pulsations of white dwarf stars as stable clocks. A subset of pulsating white dwarf stars have pulsational stability that exceeds most pulsars and rivals that of atomic clocks. A planet in orbit around such a white dwarf causes a reflex orbital motion of the star that produces a detectable change in arrival time of the pulses. The change in pulse arrival time is linearly dependent on both the mass and orbital separation of the planet. Since most stars eventually become white dwarf stars, our technique samples a wide range of stellar ages and types. Ted von Hippel (U. Texas), V. S. Meadows (JPL/Caltech), G. Tinetti (NAI-NRC/Caltech) Using Artificial Neural Networks for Analysis and Discrimination of TPF Planetary Spectra The Terrestrial Planet Finder (TPF) mission will use low-resolution spectra to characterize extrasolar terrestrial planets, with the ultimate goal of finding signatures of life in the planets' atmospheres or surfaces. The TPF mission will hopefully include both an optical coronagraph and an infrared interferometer. At this early stage, the exact wavelength range, spectral resolution or likely sensitivity of the spectrometer for either configuration has not been determined. To help understand the trade-offs for spectral characterization of terrestrial planets inherent in designing both the optical and infrared instruments, we are examining the degree to which planetary spectra can be reliably classified as a function of wavelength coverage, spectral resolution, and signal-to-noise. To do this, we have generated optical and mid-IR synthetic spectra for a range of plausible terrestrial planets, from frozen to more Earth-like worlds. We degrade these theoretical spectra to a range of spectral resolutions and S/N levels and then discern the degree to which the spectra can be distinguished using Artificial Neural Networks. Our results indicate that Artificial Neural Networks can make important distinctions between atmospheric types at the modest resolutions and signal-to-noise levels likely to be characteristic of TPF planetary spectra. We also report on the trade-off between S/N and wavelength resolution for both architectures. _____________________________________________________________________ Wm. R. Ward Department of Space Studies, Southwest Research Institute, Boulder, CO 80302. Navigating the Nebula: An Overview of Planet Migration Mechanisms. The current understanding of planet migration due to disk-planet interactions will be reviewed. Three distinct modes of migration have now been identified, and their basic operations and ranges of validity will be described. Types I and II result respectively from linear and non-linear responses of the disk to the planetary torques exerted at Lindblad resonances. The reaction torques on the planet are negative for outer resonances but positive for inner ones, and thus these resonance groups oppose each other. In a Keplerian disk, the outer resonances typically dominate, and if the planet is not large enough to open a gap in the disk, the orbit decays (type I) at a rate proportional to both the planet and disk masses. A recent suggestion that strong disk turbulence might thwart this trend will also be considered. On the other hand, when the planet is sufficiently large to shepherd material away from itself, it will open and occupy a quasi-equilibrium position in a gap, avoiding type I motion. In a viscously evolving disk, the planet will now be linked into the angular momentum transport process and forced to co-evolve with that structure. Its (type II) migration rate and direction depend on the disk properties and a variety of system end points will be described. The conditions leading to transition from type I to type II migrations will be analyzed as well. Finally, there a newly described third type of migration that arises from coorbital, corotation torques in the horseshoe zone of the planet. This torque is due to the one-time horseshoe encounter of disk material with the planet as it migrates past. When the surface density of trapped horseshoe material is equal to that of disk, the additional torque is just sufficient to force this material to migrate with the planet. However, if surface density of the trapped material is less than that of the ambient disk, there is an excess torque that can significantly increase the migration rate above the type I value. This is a particularly dangerous situation for the survival of embryos and giant planet cores. We discuss how this mode of migration could be suppressed by a sufficient disk viscosity. _____________________________________________________________________ A. J. Weinberger (CIW/DTM) and E. E. Becklin (UCLA) The Peculiar PAH Dominated Spectrum of HD 141569 The infrared spectra of most young disks are dominated by emission from small silicate grains. HD 141569, a 5 Myr old AeBe star, in contrast, shows emission solely from polycyclic aromatic hydrocarbons (PAHs). We present spatially resolved spectra of the disk taken from the Keck Observatory. The disk was detected out to 90 AU, i.e. out almost to the maximum radius of 100 AU seen in previous mid-infrared imaging. Lines from PAHs are detected at every radius, and their line-to-continuum ratios actually increase with radius. This is the opposite behavior expected if the number of PAHs remains constant or decreases with radius, because the exciting flux for the PAHs (i.e. stellar UV continuum) falls off with radius. We find a best fit for the PAH spectrum using small ionized PAHs. These are the ones most subject to radiation pressure ejection and photodestruction on short timescales. No silicate emission is observed. Qualitatively, the presence of PAHs within 100 AU and lack of crystalline silicates together favor the cold coagulation dust model of Li & Lunine (2003) for the dust production. However, the pileup of small grains at ~90 AU is difficult to explain without an enhanced production rate at that radius, as these grains should be ejected from the system quickly. _____________________________________________________________________ Peter.J. Wheatley (University of Leicester), R.G. West (University of Leicester), S.T. Hodgkin (Univ. of Cambridge, UK), D.J. Christian (QUB, UK), W.I. Clarkson (The Open University), A. Collier Cameron (St Andrews, UK), N.A. Evans(Keele University), A. Fitzsimmons(Queen's University Belfast), C.A. Haswell(The Open University), C. Hellier(Keele University), K.D. Horne(St Andrews, UK), J. Irwin (Univ. of Cambridge, UK), S.R. Kane(St Andrews, UK), F.P. Keenan(Queen's University Belfast), T.A. Lister(The Open University), A.J. Norton(Queen's University Belfast), J.P. Osborne, D. Pollacco(Queen's University Belfast), R. Ryans(Queen's University Belfast), I. Skillen(Queen's University Belfast), R.A. Street(Isaac Newton Group). Tera-scale data mining for WASP and other transit surveys The Wide Angle Search for Planets (WASP) is searching for transiting hot jupiters using an array of CCD cameras fitted with fast photographic lenses. In common with other transit search experiments, the SuperWASP instruments collect vast quantities of time-series data. In this paper we discuss the challenges presented by such large data sets and describe some of the solutions we are choosing to deploy. Our database system is designed to hold tens of terabytes of imaging and time-series data, and to serve these data efficiently to the distributed WASP consortium and, ultimately, the wider community. Our data mining system is designed to find examples of rare variable and transient objects within this database. We will present early results from this automated classification and analysis of SuperWASP light curves. _____________________________________________________________________ Josh Winn, Harvard-Smithsonian Center for Astrophysics The Case of the Mysterious Winking Star: A Pre-Main-Sequence Binary and its Circumbinary Ring The pre-main-sequence star KH 15D is famous for its periodic eclipses that are remarkably deep (3.5 mag) and long-lasting (currently over 50% of the 48-day period). It was long suspected that the eclipses are caused by circumstellar material, but the specific mechanism only recently became clear: the observed star is a member of an eccentric binary system that is gradually being occulted by the edge of a precessing, inclined, circumbinary ring. I will explain the evidence for this model, drawn from optical photometry, spectroscopy, and an analysis of archival photographs. I will also present a synthesis of the available data to determine the orbital parameters of the binary, and the geometry of the ring. There are at least two possible ways in which this system may be relevant to planet formation theory: the occulting edge can be used as a "natural coronagraph" to map out the environment of the young star; and the observed sharpness of this edge may be caused by the shepherding influence of circumbinary planets. _____________________________________________________________________ Robert A. Wittenmyer (1), William D. Cochran (2), Michael Endl (2) (1)Astronomy Department, University of Texas at Austin (2)McDonald Observatory, University of Texas at Austin Detection Limits on Planets Orbiting Nearby Stars We present a comprehensive set of precise radial velocity data obtained with the McDonald Observatory 2.7m telescope for 36 stars spanning about 15 years. The very long baseline of these data allows extremely tight constraints to be placed on potential planetary companions orbiting these stars at semimajor axes out to 5-6 AU. By placing upper limits on the mass of such planets as a function of semimajor axis, these data will provide essential constraints on the statistical frequency of extrasolar giant planets in long-period orbits. These results are necessary for the preparation of future missions such as SIM and TPF, which will explore these systems in much more detail. _____________________________________________________________________ Alex Wolszczan (Penn State) and Maciej Konacki (Caltech) A PLUTO-MASS BODY AND IONIZED GAS IN THE PSR B1257+12 PLANETARY SYSTEM We report a detection of a very low-mass body and a cloud of ionized gas orbiting the 6.2-ms radio pulsar PSR B1257+12, a rapidly spinning neutron star known since 1992 to have three terrestrial-mass planets around it. Taking advantage of a microsecond precision of the dualfrequency timing measurements of PSR B1257+12 with the 305-m Arecibo radio telescope, we have detected a 3.7-yr periodicity with a frequency dependent amplitude in the pulse times-of-arrival (TOAs) from the pulsar. Because the observed TOA variations are larger at a lower of the two observing frequencies, part of them must represent a dispersive TOA delay generated by a periodically changing electron density in the ionized medium along the line of sight traversing the pulsar planetary system. The data suggest that, in addition to the three inner planets, the pulsar has a Pluto-mass companion, which could be the most massive member of a swarm of very low-mass bodies. Circling the pulsar in a 2.7-A.U. orbit, the companion must also be embedded in a cloud of material, whose gaseous component remains ionized by the pulsar wind and contributes the observed dispersive TOA delay. _____________________________________________________________________ Jason Wright & Geoffrey Marcy (University of California, Berkeley) Using Chromospheric Ca II Emission to Study Jitter, Evolution, and Maunder Minimum Stars The detection of low-mass planets through precision Doppler measurements is hindered by radial-velocity noise of an astrophysical origin, "jitter", which is well correlated with Ca II H & K line measurements of stellar activity. We have measured activity levels for all of the California and Carnegie Planet Search Stars. We show that many stars previously identified as Maunder minimum stars, stars with very low activity levels and thus presumably very little jitter, are actually slightly evolved off the main sequence, and may not be extraordinarily inactive after all. We have used our activity measurements and Hipparcos parallaxes to demonstrate that the relation often used to derive ages of main sequence stars breaks down as a star evolves off the main sequence, and that ages derived from R'HK measurements for stars older than 2 Myr are highly uncertain. _____________________________________________________________________ Andrew Youdin (Princeton) Planetesimal Formation: Why Gas Matters I will describe how gas in protoplanetary disks both inhibits and promotes the formation of planetesimals by gravitational instability. Inhibition is accomplished by the diffusive action of gas turbulence. I will briefly review recent results on the generation of turbulence by vertical shear instabilities. Many mechanisms propose to seed planetesimal formation by concentrating particles in gaseous vortices or eddies. I will describe a particularly robust mechanism which is described by a linear streaming instability between solids and gas. I will also present recent results on the modification of gravitational instabilities by gas drag. Emphasis will be placed on the well-established (e.g. Ward, 1976) finding that gas dissipation allows slow gravitational instabilities at densities well below the Roche limit. _____________________________________________________________________ Ji-Lin Zhou (1), D. N. C. Lin (2), Yi-Sui Sun (1) (1) Department of Astronomy , Nanjing University, Nanjing 210093, China (2) UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 The Stability of Multi-Planet Systems in Large Scales We study numerically the stability of multiple planet systems with N-body simulations. The planets are set as moving in a plane, they have equal mass and being regularly spaced according to their mutual Hill's radius. The system become unstable, either orbital crossing or close encounters occur for any two of the planets, We find the time scale that instability occurs can be expressed as a power law, $\log T= B log (\Delta a) +C$, with $B$ and $C$ are constants depends on the initial eccentricities and the planet mass. This result extend those of Chambers et al.(Icarus. 119,261-268) and Yoshinaga et al (1999, Icarus, 139, 328-335) at small $Delta a$. We also show that the increasing of the planet stochastic (evolution of velocity dispersions. These results can be applied to understand the stability of N-protoplanet systems, the stable of our solar systems, as well as the possible explanation of the observed a-e distribution by n-body interactions. _____________________________________________________________________