Astronomers have detected a signal emanating from a colossal black hole in the depths of space, likely the result of a merger between two large black holes billions of light-years away. This cosmic entity is approximately 225 times more massive than the sun, marking it as the most substantial black hole observed through gravitational waves to date. The previous record for a black hole merger identified in this manner was 140 times the mass of the sun. Announced on July 14, this finding is the product of a worldwide collaboration of observatories, including two based in the U.S. The size of the black hole goes beyond expectations established by known stellar collapse processes.

“We have hypotheses regarding how black holes emerge when stars reach the end of their life cycles, and those hypotheses hold up for black holes that are five times, ten times, or even fifty times the mass of our sun,” noted Mark Hannam, a scientist from Cardiff University leading the research, on his Substack, The Fictional Aether. “However, once you exceed about 60 times the sun’s mass, peculiar nuclear/quantum/whatever processes come into play, causing the star to lose significant mass, and as a result, a truly massive black hole cannot be formed. This phenomenon persists until you arrive at exceptionally massive stars.”

Black holes represent some of the most enigmatic phenomena in the cosmos. Approximately 50 years ago, they were merely theoretical constructs. Presently, black holes are not only recognized within the scientific community but certain supermassive varieties are even having their images captured by synchronized radio dishes on Earth. Unlike planets or stars, black holes lack surfaces. They possess a boundary known as an “event horizon,” which marks a point of no return. Anything venturing too close will be pulled in, unable to break free from the grasp of the black hole’s gravity.

“Nothing can elude a black hole, not even another black hole,” Hannam clarified, “leaving behind: a larger black hole.”

The most prevalent type, termed a stellar black hole, is believed to arise from the demise of a massive star in a supernova explosion. The material of the star collapses onto itself, condensing into a relatively small region. Physics predicts a void in the sizes of black holes that can form via this process, ranging from approximately 60 to 130 times the sun’s mass, which is expected to be mostly unoccupied.

However, this merger, designated GW231123, is defying expectations, according to the LIGO-Virgo-KAGRA Collaboration, which has recorded about 300 since 2015. It involved two black holes estimated to fall within the mass gap. Researchers have also noted something intriguing about the event.

“The black holes seem to be rotating at a very high speed — near the maximum permitted by Einstein’s theory of general relativity,” stated Charlie Hoy, a scientist from the University of Portsmouth, in a statement. “This makes modeling and interpreting the signal quite challenging.”

One potential explanation is that at least one of the colliding black holes did not originate from a collapsing star, but rather from a previous merger of black holes. This scenario would necessitate extreme conditions where merged black holes could exist long enough to collide again.

The event may indicate new mechanisms by which the universe creates black holes, a concept that scientists are just beginning to explore.