Scientists have discovered a black hole merger with a mᴀss more than 225 times that of the Sun.

Canadian astronomers said that although the mᴀss of this black hole cannot be compared with supermᴀssive black holes, which can be tens of thousands to billions of times the mᴀss of the Sun and are located at the center of galaxies, “this is a quite unusual and interesting merger”.

Previously, on November 23, 2023, waves from a giant merger of two black holes impacted Earth and were collected by the LIGO-Virgo-KAGRA collaboration (a group specializing in detecting such mergers through gravitational waves). These black holes are very large, with mᴀsses 100 and 140 times that of the Sun.

Most mergers of this type detected so far using gravitational waves have been between 10 and 40 times the mᴀss of the Sun, but this one is really special because the black hole is so mᴀssive, said Sophie Bini, a postdoctoral fellow at Caltech and a member of the team.

The team that first detected gravitational waves 10 years ago has since detected more than 300 events. But this is the biggest yet, many times bigger.

Another interesting discovery from this merger – called GW231123 – is that the pair of black holes appear to be spinning extremely fast.

Charlie Hoy at the University of Portsmouth said the black holes were spinning fast, close to the limits allowed by Albert Einstein’s general theory of relativity. That makes it difficult to model and interpret the signal. It’s a great case study to advance humanity’s theoretical tools.

There are supermᴀssive black holes, which can be tens of thousands to billions of times the mᴀss of the Sun and lie at the centers of galaxies. For example, the Milky Way has a central black hole, called Sagittarius A*, or Sgr A*, which is about 4 million times the mᴀss of the Sun.

There are also stellar-mᴀss black holes, which can range from a few times the mᴀss of the Sun to tens or, some say, hundreds of times the mᴀss of the Sun. They form when a mᴀssive star runs out of fuel and explodes spectacularly, an event known as a supernova.

But there are also black holes that lie somewhere in between, called intermediate black holes. Finding these intermediate black holes has proven difficult for astronomers. This new merger falls within what astronomers call the “mᴀss gap” between stellar-mᴀss black holes and supermᴀssive black holes.