Black holes swarm in the core of a globular cluster

Astronomers have looked at the nearby globular cluster NGC 6397 and found that, instead of a single massive black hole in its core, it's likely to have dozens or even hundreds of smaller black holes swarming around in its center.

Holy Kessel Run!

Black holes play an astrophysically important role in the birth and lives of galaxies, stars, and other objects. We know of two flavors of black holes: Stellar-mass ones, from a few up to a few dozen times the mass of a star that are created when mass...