Gravitational wave detectors see two different black holes as they swallowed a neutron star
Astronomers using three different gravitational wave detectors have seen the gravity ripples caused when two different black holes swallowed a nearby neutron star.
The two gravitational-wave events, dubbed GW200105 and GW200115, rippled through detectors only 10 days apart, on January 5, 2020, and January 15, 2020, respectively.
Each merger involved a fairly small black hole (less than 10 Suns in heft) paired with an object between 1½ and 2 solar masses — right in the expected range for neutron stars. Observers caught no glow from the collisions, but given that both crashes happened roughly 900 million light-years away, spotting a flash was improbable, even if one happened — and it likely didn’t: The black holes are large enough that they would have gobbled the neutron stars whole instead of ripping them into bite-size pieces.
Note the time between the detection, in early 2020, and its announcement now, in mid-2021. The data is very complex and filled with a lot of noise, requiring many months of analysis to determine if a detection was made. For example, in a third case one detector was thought to have seen another such merger but scientists remain unsure. It might simply be noise in the system. I point this out to emphasize that thought they are much more confident in these new detections, there remains some uncertainty.
Astronomers using three different gravitational wave detectors have seen the gravity ripples caused when two different black holes swallowed a nearby neutron star.
The two gravitational-wave events, dubbed GW200105 and GW200115, rippled through detectors only 10 days apart, on January 5, 2020, and January 15, 2020, respectively.
Each merger involved a fairly small black hole (less than 10 Suns in heft) paired with an object between 1½ and 2 solar masses — right in the expected range for neutron stars. Observers caught no glow from the collisions, but given that both crashes happened roughly 900 million light-years away, spotting a flash was improbable, even if one happened — and it likely didn’t: The black holes are large enough that they would have gobbled the neutron stars whole instead of ripping them into bite-size pieces.
Note the time between the detection, in early 2020, and its announcement now, in mid-2021. The data is very complex and filled with a lot of noise, requiring many months of analysis to determine if a detection was made. For example, in a third case one detector was thought to have seen another such merger but scientists remain unsure. It might simply be noise in the system. I point this out to emphasize that thought they are much more confident in these new detections, there remains some uncertainty.