Location of M15 and M31 G1 in the northern autumn sky

Astronomers uncovered one of the black holes in the center of the globular star cluster M15, 32,000 light-years away in the constellation Pegasus. The black hole is 4,000 times more massive than our Sun. A 20,000-solar-mass black hole was found in the giant globular cluster G1, located 2.2 million light-years away in the neighboring Andromeda galaxy.