The biggest. The farthest. The most energetic. A new detection of gravitational waves from two colliding black holes has racked up multiple superlatives.
What’s more, it also marks the first definitive sighting of an intermediate mass black hole, one with a mass between 100 and 100,000 times the sun’s mass. That midsize black hole was forged when the two progenitor black holes coalesced to form a larger one with about 142 solar masses. It significantly outweighs all black holes previously detected via gravitational waves, ripples that wrinkle spacetime in the aftermath of extreme events.
“This is the big guy we’ve been waiting for, for the longest time,” says Emanuele Berti, a physicist at Johns Hopkins University who was not involved with the research. One of the behemoth’s two progenitors was itself so massive that scientists are pondering how to explain its existence.
Detected on May 21, 2019, the gravitational waves originated from a source about 17 billion light-years from Earth, making this the most distant detection confirmed so far. Because of the expansion of the universe, that distance corresponds to a travel time of about 7 billion years, meaning that the gravitational waves were emitted when the universe was about half its current age. It’s also the most energetic event yet seen, radiating about eight times the equivalent of the sun’s mass in energy, says astrophysicist Karan Jani of Vanderbilt University in Nashville, a member of the LIGO Scientific Collaboration. “I hope it deserves its own entry in the record book.”