The gravitational wave hunters are still crouched in their laboratories obsessively listening to the run-run in the background left by the creation of the Universe. And they do it, above all, because in recent years they have not won for surprises. One after another, North American and European teams have managed to go deeper into that fundamental cosmological plot.
Now, for the first time, LIGO and Virgo researchers have confirmed the detection of a collision between a black hole and a neutron star. It’s more, they found not one but two of these events only 10 days apart. This occurred about 900 million light years from Earth and was detected in January 2020.
A cosmological puzzle whose pieces are beginning to fit together
The first event was detected on January 5, 2020 and involved a black hole of a mass equivalent to nine solar masses and a neutron star of just 1.9 solar masses. The second was detected on January 15 and was led by two slightly smaller objects (the black hole had about six solar masses and a star, one and a half sun).
The result of each of these encounters is what we would expect from an exercise in cosmic bullying: Everything seems to indicate that the neutron stars ended up being completely swallowed up by the black hole. Quite a spectacle of stellar savagery without a doubt. However, that is not the most interesting.
Beyond confirming the cosmological violence in the Ligo and Virgo detectors, what this work reflects is that there are binary systems formed by a black hole and a neutron star. Something that we were not too clear about and that, we didn’t even know we could observe them thanks to gravitational waves. Gravitational astronomy is gaining weight and this begins to change the way we look at the universe.