Astronomers have discovered a black hole “unlike any other” housed in a star cluster in the nearby Andromeda Galaxy. The “intermediate mass” object is thought to be one of a rare third type of the cosmic phenomena that could be the ‘missing link’ to understanding the evolution of black holes.
The findings, published recently in the Astrophysical Journal, show that the object has a mass 100,000 times greater than the Sun. This makes it smaller than supermassive black holes located at the center of galaxies, but larger than the stellar black holes formed when stars explode.
Using observational data from the Gemini North telescope in Hawaii, the researchers identified the intermediate black hole (IMBH) in a massive star cluster (called B023-G078) that is more than 6 million times the mass of the Sun. The authors argue that the cluster is a “stripped nucleus,” the remnant of a smaller galaxy that fell into a larger one and had its outer stars snatched away by gravitational forces.