Researchers found two black holes where they weren't expecting to, and then they found another.
The black holes were found in globular cluster M62 in the constellation Ophiuchus, located about 22,000 light-years away; globular clusters are "some of the oldest and densest collections of stars in the universe," a Michigan State University news release reported.
Last year when the research team discovered the two black holes they weren't sure if it meant they were incredibly lucky, or if the objects were actually commonplace in globular clusters. The discovery of the third black hole suggests they are actually a common occurrence in the extremely dense areas.
"This implies that the discovery of the other black hole, in the globular cluster called M22, was not just a fluke," Laura Chomiuk, team member and MSU assistant professor of physics and astronomy, said. "Black holes really may be common in globular clusters."
Black holes are stars that have died and collapsed in on themselves. The objects have such strong gravitational forces that even light remains trapped in their midst.
Until very recently scientists believed that black holes could not occur in dense globular clusters because these regions are a million times more closely packed than the stars in our own solar neighborhood.
"There are so many stars in such a condensed area that they often interact with one another. Massive black holes would have the most violent encounters, 'sling-shotting' each other out of the cluster," the news release reported.
The team was "surprised" to find the original two black holes in M62 because they had believed if two of the objects were packed that closely together one would have to push the other out of the cluster eventually; this new finding may have proven them wrong.
"I think it's safe to say that we have discovered a whole new hunting ground for black holes," Chomiuk said.
More research will be needed in order to confirm the object is a black hole.
