The Star Grinder: A Cloud of Black Holes at the Center of the Milky Way

There is a supermassive black hole at the center of our galaxy. There is also a lot of other stuff there as well. Young stars, gas, dust, and stellar-mass black holes. It's a happening place. It is also surrounded by a veil of interstellar gas and dust, which means we can't observe the region in visible light. We can observe stars in the region through infrared and radio, and some of the gas there emits radio light, but the stellar-mass black holes remain mostly a mystery.

One big challenge is that we don't have a good measure of how many black holes are there. Traditional models of star formation suggest there may be as few as 300 in the closest region of the supermassive black hole Sagittarius A. Other models suggest that the formation of Sag A itself may have triggered the formation of hundreds of stellar-mass black holes. But a new study in Astronomy & Astrophysics suggests the number of stellar-mass black holes is much higher.