Black hole tears apart massive star in rare cosmic spectacle dubbed 'the Whippet'

In early January, astronomers gathered in Phoenix for their annual conference with news of a cosmic violence so extreme it rewrote what they thought possible. A black hole had caught a massive star and torn it to pieces—not gradually, but in a burst of energy so fierce that for a moment it blazed 400 billion times brighter than our sun. The event, catalogued as AT2024wpp and given the nickname "the Whippet," exceeded even the most violent supernovae ever recorded.

Anna Ho, an astronomer at Cornell University, spotted the signature first. Using the Zwicky Transient Facility at Palomar Observatory in California, she caught the light from the explosion almost as soon as it reached Earth. Within hours, the team recognized what they were seeing: a Luminous Fast Blue Optical Transient, or LFBOT—a rare and poorly understood type of stellar catastrophe. Within a day, observations from the Liverpool Telescope in the Canary Islands and NASA's Swift satellite confirmed the diagnosis. The object was intensely blue and producing X-rays, exactly what theory predicted for a star being consumed by a black hole's gravity.

Daniel Perley, an astrophysicist at Liverpool John Moores University and lead author of the paper now being prepared for the Monthly Notices of the Royal Astronomical Society, described the moment of realization to the conference. The team had discovered a black hole in the act of shredding a companion star, pulling its material into a disk that spiraled inward to feed the black hole's hunger. "Even though we suspected what it was, it was still extraordinary," Perley said. The energy released dwarfed anything powered by stellar collapse alone. Colleagues at UCLA and Caltech provided distance measurements that confirmed the object was genuinely far more luminous than any normal supernova, cementing the interpretation.

What made this event scientifically precious was not just its power but what it revealed about black holes themselves. These tidal disruption events—where a black hole's gravity tears a star apart—had been observed before, but never at this scale. "Not only do these events help us identify black holes, they provide a new way to identify where black holes occur and how they form and grow," Perley explained. The Whippet offered a window into black hole behavior that conventional observations could not match.

The mechanics of the destruction unfolded in a traceable sequence. As material from the shredded star spiraled inward, it heated to extreme temperatures and released both X-ray radiation and a powerful wind of gas. This wind crashed into material the star had shed earlier in its death throes, producing the brilliant blue and ultraviolet light detected in the first few days, along with radio and millimeter emissions. A shock wave propagated outward at one-fifth the speed of light through the surrounding gas, but after about six months, it simply fizzled out once it reached the edge of the bubble carved by the star's earlier ejections.

Yet the event left behind a puzzle that remains unsolved. For the first month after the explosion, spectroscopic observations from the Keck Observatory, Magellan Observatory, and the Very Large Telescope showed no recognizable chemical signatures. Then, as the transient faded, weak traces of hydrogen and helium began to appear. The helium was moving at more than 6,000 kilometers per second along the line of sight toward Earth—far faster than expected, suggesting something dense and tightly bound had survived the blast intact. The team has two competing theories. The helium could be a stream of material torn from the star's core as the black hole's gravity wrenched it apart. Alternatively, it might originate from a third object in the system, blasted by the intense wind and radiation pouring from the black hole. Either way, the Whippet has opened new questions about how stars die when gravity becomes absolute.