Astronomers detected an ultrabright tidal disruption event from an orphan supermassive black hole located more than 30,000 light-years away from the center of its host galaxy, roughly 750 million light-years away in the constellation Cetus. The discovery validates a new artificial intelligence technique used to hunt for wandering black holes.
A team of researchers has captured direct evidence of a wandering supermassive black hole shredding a star far from any galactic core. First flagged in November 2025 by the Zwicky Transient Facility, the event was cataloged as AT2024tvd in a distant galaxy located about 750 million light-years away in the constellation Cetus.
How Artificial Intelligence Spotted the Off-Center Flare
Astronomers rely on tidal disruption events—the intense gravitational shredding that occurs when a star drifts too close to a massive black hole—to find otherwise invisible heavyweights. Nearly every galaxy in the universe anchors a supermassive black hole at its center, where roughly once every 100,000 years a star wanders too close.
Surveys typically spot about 30 such events each year, but prior to 2024, they’d only been seen in galaxy cores. That changed when a new artificial intelligence algorithm sifted through half a million nightly flashes caught by the Palomar Observatory survey in Southern California.
“Out of the half million flashes ZTF detects each night, our new artificial intelligence algorithm automatically recognized a flare that looked a lot like a tidal disruption event, despite its unusual location in the outskirts of a galaxy.”
For a few months, the tidal disruption event outshone its host galaxy in ultraviolet wavelengths, radiating temporarily with the light of about 10 billion suns. Follow-up observations with the SOAR telescope in Chile analyzed the event’s spectrum, while NASA’s Neil Gehrels Swift Observatory captured wavelengths inaccessible from the ground. Swift’s Ultraviolet/Optical Telescope measured the blip’s temperature at about 54,000 degrees Fahrenheit, or 30,000 degrees Celsius.
Weighing the Evidence and Tracing the Orphan’s Origins
Confirming the unusual find required ruling out competing astronomical explanations through multi-telescope coordination. Jonathan Carney, a doctoral student at the University of North Carolina at Chapel Hill who took the first spectra supporting the event, noted that the combination of all this data helped us rule out other explanations and confidently say it’s a tidal disruption event, despite its strange location.
Researchers estimate the runaway black hole weighs in at approximately one million times the mass of the Sun. Because wandering black holes emit almost nothing when they are not actively consuming matter, the sudden destruction of a star serves as a temporary signal.
Investigators have proposed two main scenarios for how the black hole ended up stranded in the galactic halo. In the first model, three or more galaxies merged, and a gravitational tug-of-war among their central supermassive black holes may have flung the lightest one out toward the edge. Alternatively, a dwarf galaxy could be midway through a merger, having left its central black hole drifting as its stars fell into the larger galaxy.
Validating a Technique for a Future Cosmic Census
Scientists want to answer a fundamental question: How common are wandering black holes? Detecting them via stellar destruction confirms that theoretical populations of off-center black holes predicted by galaxy growth simulations actually exist.
Future sky surveys promise to turn these isolated discoveries into a true cosmic census. Telescopes such as the future Vera C. Rubin Observatory are expected to detect more similar events, while the Nancy Grace Roman Space Telescope will search for more distant cases.
Meanwhile, pointed science observations involving Swift’s UVOT and X-Ray Telescope instruments remain temporarily suspended as the mission awaits an orbit boost planned for this summer.
