“An international team of astronomers has captured the first-ever polarized radio waves from a distant cosmic explosion.
This explosive event (known as gamma-ray burst GRB 190114C) is part of a class of the most energetic explosions in the universe. It was produced when a star — much more massive than our sun — collapsed to form a black hole.
Gamma ray bursts produce powerful jets that travel close to the speed of light and shine with the incredible luminosity of more than a billion suns combined. Astronomers have struggled to understand how these jets are formed and why they seem to appear only in gamma ray bursts — but not other explosions, such as ordinary supernovae.
Because these jets are extremely bright at radio wavelengths, the discovery of polarized radio signals may offer new clues to help solve this mystery. Polarization is a property of light that indicates how a magnetic field is organized and structured in a jet.
“We know that only a very tiny fraction (less than 1%) of massive stars form jets when they collapse,” said Northwestern University’s Raffaella Margutti, who contributed to the study. “But we have not known how they manage to launch these outflows with such extreme properties, and we don’t know why only a few stars do this….””
Read the full Northwestern News article, “Astronomers uncover first polarized radio signals from gamma-ray burst“.
Round Up of Media Mentions of CIERA/Northwestern
- Xinhua, “Astronomers capture first polarized radio signals from gamma-ray burst” by Shi Yinglun
Video credit: Kitty Yeung (art), Tanmoy Laskar (animation)