Almost all known black holes come in two sizes: small and gigantic. Data suggests intermediate-sized ones exist, but they're rare.
Astronomers using @NASAHubble have found evidence of one in a star cluster about 6,000 light-years away: go.nasa.gov/3WBaMys
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NASA's Hubble Hunts for Intermediate-Sized Black Hole Close to Home
Astronomers using Hubble have come up with what they say is some of their best evidence yet for the presence of a rare class of "intermediate-sized" black hole that may be lurking in the heart of the closest globular star cluster to Earth.Andrea Gianopoulos (NASA)