Black holes swallow neutron stars in front of astronomers


Talk about heavy snacks. Astronomers have witnessed for the first time a black hole swallowing a neutron star—the densest object in the universe.

Ten days later, they saw the same thing on the other side of the universe. In both cases, the orbit of a neutron star-one teaspoon weighing 1 billion tons-is getting closer and closer to the final point of no return, a black hole, until they finally collide together and the neutron star gobbles it up.

Astronomers witnessed the last 500 orbits of the neutron star before it was swallowed. This process took less than a minute and briefly produced as much energy as all visible light in the observable universe.

“It’s just a big quick [gulp], Disappeared,” said Patrick Brady, a co-author of the study and an astrophysicist at the University of Wisconsin-Milwaukee. The black hole “got a good meal from a neutron star and made itself a little bigger. “

This is an artistic image inspired by the black hole-neutron star merger event, which astronomers witnessed in the form of gravitational waves triggered by the event. (Carl Knox/Ozgrave/Swinburne)

When the detectors on Earth discovered the merged gravitational waves, they discovered the energy bursts produced by the collisions. This is the theory first proposed by Albert Einstein. The cosmic energy ripples soar in space and time. Each of them came from a billion light years away.These waves were detected in January 2020, but this study of more than 100 scientists analyzing and interpreting the data was published on Tuesday Astrophysical Journal Letters.

The first time in this combination

Although astronomers have seen gravitational waves Two black holes collided With each other Two neutron stars collide with each other, This is the first time they have seen a person bump into each other.

A neutron star is the corpse of a massive star, what remains after a large star dies in a supernova explosion. Brady said they are very dense, with a mass about 1.5 to 2 times the mass of the sun, but the width after compression is about 10 kilometers. Some black holes, called stellar black holes, are created when larger stars collapse on themselves, and the resulting things have such a strong gravitational force that even light cannot escape.

Scientists believe that there should be many such neutron stars paired with black holes, but they have not yet found one in our own galaxy.

“It’s very cool,” said Marc Kamionkowski, an astrophysicist at Johns Hopkins University, who was not involved in the research. He said this will help astronomers predict the number of these pairs.



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