All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 – 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Astronomers have announced new evidence that an intermediate-mass black hole (IMBH) weighing 2,200 Suns is hiding at the center of the globular star cluster 47 Tucanae.
An international team of astronomers led by Ivan Zolotukhin from Lomonosov Moscow State University is close to understanding one of the most important mysteries of modern astronomy — so-called intermediate-mass black holes. The researchers acknowledge the invaluable assistance of volunteer Russian computer programmers in the search.