Scientists confirm the existence of a rare type of black hole.
Dying stars form modest black holes measuring up to around 25 times the mass of our sun. At the opposite extreme, most large galaxies contain a supermassive black hole with a mass tens of thousands of times greater. But in a galaxy about 12 million light-years away, scientists have found evidence that points to the existence of a rare breed of black hole weighing somewhere in between. The object, called M82 X-1, is the brightest X-ray source in the galaxy Messier 82. While astronomers have suspected it of being a midsize, or intermediate-mass, black hole for at least a decade, an accurate determination of its mass hasn’t been made until now. Using archival data from NASA’s Rossi X-ray Timing Explorer satellite, astronomers discovered that M82 X-1 weighs about 400 times the sun's mass, placing it among the few midsize black holes known. Watch the video to learn more.