Artist’s concept of a scene that could occur when a black hole and neutron star meet, in a galaxy far, far away. Image via ANU.
Scientists announced today (August 19, 2019) that they believe they’ve detected a black hole swallowing a neutron star. Both of these objects represent the super-dense remains of dead stars. In this case, they reside 900 million light-years away – far from our Milky Way galaxy – so we know their meeting, if it happened, took place 900 million years ago. It has taken all those years for gravitational waves – ripples in space and time created in their meeting – to travel to Earth, to be sensed finally on Wednesday, August 14, 2019, via a trio of gravitational-wave detectors in the United States and Italy.
Scientists are sounding cautiously excited about this detection. Writing in Science on August 16, 2019, Andrew Cho said:
Gravitational-wave hunters may have spotted their most exotic quarry yet. On 14 August at 5:10:39 p.m. EDT, a trio of gigantic detectors in the United States and Italy detected a pulse of gravitational waves — ripples in space itself — apparently set off when a black hole and a neutron star ...