Black Hole Seen Swallowing Densest Object in Universe

Talk about a heavy snack. For the first time, astronomers have witnessed a black hole swallowing a neutron star, the most dense object in the universe—all in a split-second gulp. Ten days later they saw the same thing, on the other side of the universe, the AP reports. In both cases, a neutron star—a teaspoon of which would weigh a billion tons—orbits ever closer to that ultimate point of no return, a black hole, until they crash together and the neutron star is gone in a gobble. Astronomers witnessed the last 500 orbits before the neutron stars were swallowed, a process that took far less than a minute and briefly generated as much energy as all the visible light in the observable universe. More:

• Study co-author Patrick Brady, an astrophysicist at the University of Wisconsin-Milwaukee puts it like so: The black hole "gets a nice dinner of a neutron star and makes itself just a little bit more massive."

• The waves were discovered in January 2020 when detectors on Earth spotted the mergers' gravitational waves. They came from more than a billion light-years away. While astronomers had seen gravitational waves from two black holes colliding with each other and two neutron stars colliding with each other, this is the first time they saw one of each crashing together.
• Neutron stars are corpses of massive stars, what's left after a big star dies in a supernova explosion. They are dense: 1.5 to 2 times the mass of our sun condensed to about 6 miles wide.
• The study interpreting the data by more than 100 scientists was published Tuesday in Astrophysical Journal Letters. Johns Hopkins astrophysicist Marc Kamionkowski, who wasn't part of the research, said the findings will help astronomers predict how abundant these pairings are. "This is very cool," he said.

(More black holes stories.)