In a scene straight out of science fiction, astronomers using NASA’s Hubble Space Telescope have spotted a massive black hole snacking on a star, 600 million light-years away.
This rare event, called a tidal disruption event (TDE), occurs when a star ventures too close to a black hole’s immense gravitational pull and gets shredded apart.
The ripped fragments spiral around the black hole, producing a flash of light bright enough to be seen across the universe.
This particular TDE, named AT2024tvd, is unique because it didn’t happen at the center of its host galaxy.
Normally, supermassive black holes—those millions or even billions of times the mass of our Sun—are anchored in the heart of their galaxies.
But AT2024tvd is different. It revealed the presence of a “wandering” black hole, roaming through the outskirts of the galaxy, far from its central counterpart. This is the first time a TDE has been observed so far from a galaxy’s core.
What’s even more intriguing is that the galaxy actually hosts two massive black holes: one 100 million times the mass of the Sun at the center, and this smaller, wandering one weighing about 1 million solar masses.
Despite their close proximity—just 2,600 light-years apart—the two black holes are not gravitationally linked. This means they orbit separately, with the smaller one slowly drifting through the galaxy’s outer regions.
Astronomers used NASA’s Chandra X-ray Observatory and the NRAO Very Large Array to confirm the black hole’s offset position. Hubble’s sharp ultraviolet imaging provided even more clarity, pinpointing the exact spot of the TDE, far from the galaxy’s core.
The star’s destruction also sent out bright flares of light, which were first detected by the Zwicky Transient Facility at Caltech’s Palomar Observatory.
Unlike supernovae, which are also very bright, the flare from this event showed distinct signs of a black hole’s feeding frenzy—broad emission lines of elements like hydrogen, helium, carbon, nitrogen, and silicon.
Scientists are still puzzled as to how this black hole ended up in such an odd location. One possibility is that it was ejected during a dramatic three-body interaction, where two black holes collided and flung the smallest one away.
Another idea is that it’s the leftover core of a smaller galaxy that merged with its current host long ago. However, Hubble images showed no obvious signs of a past galaxy merger, leaving its origin a mystery for now.
The discovery of AT2024tvd opens new possibilities for finding more roaming black holes across the universe. Until now, these wandering giants were largely hidden from view, but TDEs might just be the key to tracking them down.
According to lead study author Yuhan Yao of UC Berkeley, this discovery might inspire scientists to search for more offset TDEs, unlocking a hidden population of supermassive black holes.
