Detecting A Devoured Dwarf

Researchers using Hubble have found a smattering of large blue stars surrounding a middleweight black hole. It's a curious assemblage that astronomers are interpreting as evidence of a recent galactic homicide.

The theory is intriguing. Black holes are generally found at the center of galaxies, but this smallish one is accompanied only by the blue stars. Researchers theorize the black hole was once at the center of a dwarf galaxy which was swallowed up by a larger galaxy, leaving the black hole alone. The digestion of the dwarf compressed gas and dust clouds near the black hole, creating the blue stars. If the theory is correct, there's even a time for the crime. Large blue stars burn very hot and die very young. Astronomers calculate, based on the blue stars, that the dwarf was destroyed and the stars created only about 200 million years ago.