Break out the cigars! Open the Gender Reveal box! Start saving for college! For the first time in history, astronomers have witnessed the birth of a black hole. As befitting of such a monumental event, they’ve named the baby black star “The Cow.” Wait … what?
“We thought it must be a supernova. But what we observed challenged our current notions of stellar death. We knew right away that this source went from inactive to peak luminosity within just a few days. That was enough to get everybody excited because it was so unusual and, by astronomical standards, it was very close by.”
According to the press release, what a team led by Northwestern University astrophysicist and assistant professor of physics and astronomy Raffaella Margutti saw was AT2018cow (‘cow’ letters generated randomly, hence the inappropriate nickname), an anomaly that flared up in the Hercules constellation in the galaxy CGCG 137-068 on June 17, 2018 … and then disappeared just 16 days later. “Flare” doesn’t do justice to this event – it was up to 100 times brighter than a typical supernova and blew out particles at 30,000 km per second (1/10th the speed of light). The event was made more exciting by its close proximity – just 200 million light years away. But Margutti and her team weren’t sure what they saw.
That’s when luck entered the picture. The team switched from the ATLAS survey’s twin telescopes (the AT part of the name) to NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and INTEGRAL hard X-ray laboratories, soft X-rays at XMM-Newton and radio antennae at the Very Large Array. All of that astronomy horsepower benefited from the fact that The Cow had much less stellar debris floating around it that similar explosions, allowing them to see clearly into its center and identify evidence of hydrogen and helium – all the signs of a baby black hole. That’s when the champagne was uncorked.
“We think that ‘The Cow’ is the formation of an accreting 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. Never.”
Margutti held the baby black hole reveal party (aka announcement) at the 233rd Meeting of the American Astronomical in Seattle this week and the research will be published shortly in the Astrophysical Journal. (Pictures of The Cow can be seen here.) Is this a big deal? We in the U.S. have just seen the adulation heaped upon a college freshman for quarterbacking his team to the national championship. Freshman studying science rather than football defenses don’t normally get that kind of attention or excitement. First-year Northwestern undergraduate student Daniel Brethauer did as part of the team.
“Being given the opportunity to contribute to something as cutting edge and international as understanding AT2018cow as an undergrad is a surreal experience. To have helped the world’s experts figure out what AT2018cow is even in the smallest way was beyond my wildest expectations at the beginning of the summer and something that I will remember for the rest of my life.”
All together now … Holy Cow!