Thanks to the Hubble telescope, astronomers have discovered a wandering supermassive black hole. It revealed its presence when it ripped apart and swallowed a star.
Wandering gravity giant
The discovery was made while studying a galaxy 600 million light-years away from the Milky Way. In 2024, ground-based telescopes detected a flare comparable in brightness to a supernova. But astronomers quickly realized that the source was a very different event — the tidal collapse of a star that got too close to the supermassive black hole. This is evidenced both by the high flare temperature and the presence of broad emission lines of hydrogen, helium, carbon, nitrogen, and silicon in its spectrum.
To further study the flare, astronomers used the Hubble and Chandra telescopes, as well as the VLA radio observatory. The data they collected revealed something surprising. The black hole that destroyed the star, whose mass is a million times greater than the solar mass, is not at all in the center of the galaxy, as one might expect. It’s actually displaced from it by a distance of about 2,600 light-years. That’s about one-tenth the distance between the Sun and the center of the Milky Way.
What’s even more curious is that at the center of the galaxy is another, much more massive black hole. Its mass is 100 million times that of the Sun. It absorbs the gas falling on it and is categorized as active.
Origin unknown
According to researchers, although two supermassive black holes coexist in the same galaxy, they are in no way connected to each other by gravitational ties. This raises the question of how the black hole came to be so far off-center.
Previous theoretical studies have shown that as three black holes interact, the least massive member can be ejected outward. Given the proximity of the wandering black hole to the central black hole, this is a possible scenario.
An alternative explanation is that the black hole is the surviving remnant of a smaller galaxy that merged with its host galaxy over a billion years ago. If so, the smaller black hole could eventually spiral and merge with the central active black hole in the very distant future.
According to NASA
