2 Sep 2020 — On May 21, 2019, LIGO/Virgo researchers detected a signal from the most massive black hole merger yet observed in gravitational waves. The product of the merger is the first clear detection of an “intermediate-mass” black hole, with a mass between 100 and 1,000 times that of the sun.
The detected signal, labeled GW190521, was generated by a source that is roughly 5 gigaparsecs away, making it one of the most distant gravitational-wave sources detected so far. This newest merger appears to be the most massive yet, involving two inspiraling black holes with masses about 85 and 66 times the mass of the sun. The merger created an even more massive black hole, of about 142 solar masses, and released an enormous amount of energy, equivalent to around 8 solar masses.
For more details, read the full press release and see the GW190521 detection page.