Hubble Space Telescope revealed the strongesr evidence for mid-sized black holes in the universe. Hubble has also confirmed that this "intermediate-mass" black hole dwells inside a dense star. Intermediate-mass black holes (IMBHs) are a long-sought 'missing link' in black hole evolution. There have been a few other IMBH candidates found to date.

Axar.az reports that they are smaller than then supermassive black holes that lie at the crores of large galazies but larger than stellar-mass black holes formed by the collapse of massive stars. This news black hole is over 50,000 times the mass of our Sun. IMBHs are hard to find.