New submitter xonen shares a report from NPR: For decades, scientists have thought that black holes should sink to the center of galaxies and accumulate there. But scientists had no proof that these exotic objects had actually gathered together in the center of the Milky Way. Isolated black holes are almost impossible to detect, but black holes that have a companion -- an orbiting star -- interact with that star in ways that allow the pair to be spotted by telltale X-ray emissions. The team searched for those signals in a region stretching about three light-years out from our galaxy's central supermassive black hole. What they found there: a dozen black holes paired up with stars. Finding so many in such a small region is significant, because until now scientists have found evidence of only about five dozen black holes throughout the entire galaxy. What they've found should help theorists make better predictions about how many cosmic smashups might occur and generate detectable gravitational waves. The study has been published in the journal Nature.