On January 5, 2020, Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States discovered a gravitational wave — ripples in the spacetime itself -coming from a merger of a black hole -a place in space with gravity so high that even light cannot escape, and a neutron star - the collapsed core of a supergiant star. This was the first gravitational wave coming from the merger of a black hole and a neutron star. Since 2016, when the first-ever gravitational wave was detected confirming Albert Einstein’s prediction, all the gravitational waves scientists were able to detect came from two black holes merging into each other or two neutron stars colliding into each other. The detection, which still had to undergo the rigorous test of scientific scrutiny, came as a fresh breeze to the astrophysicists’ community. Shooting the astronomers’ excitement to the stars, the observatory detected another gravitational wave, this too coming from another merger of a black hole and a neutron star, on January 15.
Scientists tested the signals against stringent quality checks and confirmed them to be true. They found that the first wave came from a cosmic event in which a neutron star with mass 1.9 times that of the sun merged into a black hole nine times heavier than the sun.
“We’ve now seen the first examples of black holes merging with neutron stars, so we know that they’re out there," said Maya Fishbach, one of the astronomers and a NASA Einstein Postdoctoral Fellow, in a news release by the Northwestern University in the United States. The findings were published in the Astrophysical Journal Letters on June 29.
The long list of research authors includes the name of Anjali Yelikar, who is from Hyderabad and doing her PhD at Rochester Institute of Technology. Yelikar was an undergraduate student when the gravitational waves were first detected in 2016. Now, “It’s a real dream come true to be a part of a discovery like this,” she said in a statement by Rochester Institute of Technology.