Heaviest black hole merger is among three recent gravitational wave discoveries
Scientists observed what appears to be a bulked-up black hole tangling with a more ordinary one. The research team, which includes physicists from the University of Maryland, detected two black holes merging, but one of the black holes was 1 1/2 times more massive than any ever observed in a black hole collision. The researchers believe the heavier black hole in the pair may be the result of a previous merger between two black holes.This type of hierarchical combining of black holes has been hypothesized in the past but the observed event, labeled GW190521, would be the first evidence for such activity. The Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration (LSC) and Virgo Collaboration announced the discovery in two papers published September 2, 2020, in the journals Physical Review Letters and Astrophysical Journal Letters.