A NASA concept drawing of a black hole. (Photo : NASA)
A group astronomers have discovered a surprising find in the globular star cluster Messier 22 more than 10,000 light-years from our Earth: twin black holes.
The scientists were looking for a rare intermediate-mass black hole when they stumbled upon this oddity.
"I had actually suggested several years ago that there were probably black holes lurking among the X-ray sources that had already been seen in globular clusters, and that the one way to pick the black holes sucking gas in, apart from other types of faint X-ray sources, would be to look for the radio emission, but I didn't expect that this particular cluster would be the best place to look," said Dr. Tom Maccarone, one of the authors of the paper published in the journal Nature.
Like Us on Facebook
Multiple black holes can exist in the early stages of a star cluster's life, but the reason this find is so strange is because according to computer simulations, the black holes should have started a deadly dance around each other until all but one were thrown out of the cluster.
"There is supposed to be only one survivor possible," says Jay Strader of Michigan State University and the Harvard-Smithsonian Center for Astrophysics. "Finding two black holes, instead of one, in this globular cluster definitely changes the picture."
Black holes have such an intense gravitational pull that even light cannot escape them - making them essentially invisible - so scientists have to look for other indicators that a black hole exists. The twin black holes are also the first ones to be discovered via radio, not X-Ray emissions, and are the first stellar-mass black holes to be found in a globular star cluster in our Milky Way galaxy.
Stellar-mass black holes are the smallest type of black hole, with masses several times that of our sun. Intermediate-mass black holes are the next heaviest, with supermassive black holes sporting masses of several billion suns. Many galaxies are believed to have supermassive black holes in their center.
A demonstration of how twin black holes work: