New research reveals hundreds of undiscovered black holes

8 September 2016 Astronomy Now

It is only as recently as 2013 that astrophysicists found individual black holes in globular clusters via rare phenomena in which a companion star donates material to the black hole. New research by the University of Surrey on a globular cluster known as NGC 6101 shows that it could host several hundred black holes — a phenomenon that until recently was thought impossible.