The Laser Interferometer Gravitational-wave Observatory (LIGO) is no stranger to making history and breaking records. In 2015, its twin detectors based in Livingston, Louisiana, and Hanford, Washington, made the first ever detection of gravitational waves.

The massive black hole has been dubbed GW231123. Its unusual size and behavior is challenging scientists' understanding of black hole formation, Hannam said. Previously, the largest known black hole that came from a merger was about 140 times the mass of the sun.