American astronomers published a paper in the latest issue of the Astrophysical Journal Express, saying that they had found the nearest supermassive black hole pair with the help of multi-band observation, which is only 750 light-years away from each other. The two ghostly black holes are heading for a fierce confrontation. This discovery helps astronomers better estimate how many supermassive black holes in the universe are also close to collision, thus further revealing the secret of gravitational waves. The newly discovered supermassive black hole is located in a mixture of two galaxies that collided about 480 million light-years from the earth. There are supermassive black holes in the center of most galaxies. The mass of these two black holes is 200 million times that of the sun and 125 million times that of the sun. Previously, when scientists observed the two galaxies, they only saw a supermassive black hole. Because the distance between the two black holes was too close, it was impossible to distinguish them with a telescope. In the latest study, Kiara Mingarelli, an associate researcher of the Center for Computational Astrophysics at the Iron Institute in New York, and others, combined with 12 observations from seven telescopes, including the Hubble Space Telescope of the National Aeronautics and Space Administration (NASA), finally revealed two different black holes. Mingarelli said that the distance between the newly discovered black hole pairs "is close to the limit of detection, which is why this discovery is so exciting, which means that supermassive black holes that will be in close contact may be more common than expected, and they will produce a large number of ultra-strong gravitational waves". Researchers said that although the two supermassive black holes are only 750 light-years apart, they will not merge in hundreds of millions of years. (Outlook New Era)