Astronomers using NASA’s Chandra X-ray Observatory have found a quartet of pronounced X-ray cavities in RBS 797, a cluster of galaxies located about 3.9 billion light-years away in the constellation of Draco. This suggests there is a pair of closely orbiting supermassive black holes, both of which erupted and generated jets at about the same time. If confirmed, these black holes would be among the closest pair ever discovered, with a separation...
