Prior to last summer, the world had never seen the birth of a black hole or neutron star.
“We know from theory that black holes and neutron stars form when a star dies, but we’ve never seen them right after they are born,” says Raffaella Margutti, physics and astronomy and a member of the Center for Interdisciplinary Exploration and Research in Astrophysics. “Never.”
On June 17, 2018, an international team lead by Margutti, was alerted to a mysteriously bright object that burst in the northern sky. On that night, the ATLAS survey’s twin telescopes in Hawaii found a spectacularly bright anomaly 200 million light years away in the Hercules constellation. Dubbed AT2018cow or “The Cow,” the object quickly flared up, then vanished almost as quickly.
After combining several imaging sources, including hard X-rays and radiowaves, the multi-institutional team now speculates that the telescopes captured the exact moment a star collapsed to form a compact object, such as a black hole or neutron star. The stellar debris, approaching and swirling around the object’s event horizon, caused the remarkably bright glow.
Margutti will discuss the discovery and others that have revolutionized our understanding of phenomena that we thought we already knew at the May’s Science Café. The event takes place on May 22 from 6:30 to 8 p.m. at the Firehouse Grill, 750 Chicago Ave. in Evanston. Northwestern’s Science Café is free to attend and open to the public.