Scientists Discover What May Be the Largest Black Hole Yet

Aug 12, 2025 - Scientists have possibly discovered the largest black hole ever detected in the universe. The gigantic black hole's size is said to be close to the theoretical upper limit of what is possible in the universe.

According to the study, this black hole has a mass equivalent to 36.3 billion suns, with a margin of error of about 6 billion solar masses.

Among the Top 10

Professor Thomas Collett from the University of Portsmouth said this is one of the top 10 most massive black holes ever found - and possibly the largest.

It lies at the centre of a galaxy whose light is distorted into the shape of a horseshoe as it passes through another massive galaxy in front of it. This unique visual distortion has earned the galaxy the nickname "Cosmic Horseshoe."

5 Billion Light-Years Away

This ultramassive black hole is located approximately 5 billion light-years from Earth. The newly-discovered black hole has been dubbed a "dormant" black hole

Brazilian researcher Charlos Melo noted that it is currently inactive, meaning it is neither consuming matter in its surroundings nor ejecting it.

Formed Through Mergers

According to Collett, the Cosmic Horseshoe galaxy is a "fossil group" galaxy, which is in its final stage of evolution. It is likely that the black holes from neighbouring galaxies merged into this one, resulting in its enormous size.

It is 10,000 times heavier than the black hole at the centre of our own Milky Way galaxy, Sagittarius A*, which holds a mass of 4.15 million suns. Sagittarius A* is also a dormant black hole.

 “Most of the other black hole mass measurements are indirect and have quite large uncertainties, so we really don't know for sure which is biggest,” said Collett, adding, “However, we've got much more certainty about the mass of this black hole thanks to our new method.”