“But in AT2018hyz there was radio silence for the first three years, and now it’s dramatically lit up to become one of the most radio luminous TDEs ever observed.” “We have been studying TDEs with radio telescopes for more than a decade, and we sometimes find they shine in radio waves as they spew out material while the star is first being consumed by the black hole,” says Edo Berger, professor of astronomy at Harvard University and the CfA, and co-author on the new study. Radio observations of the TDE proved the most striking. The team collected observations of the TDE, dubbed AT2018hyz, in multiple wavelengths of light using the VLA, the ALMA Observatory in Chile, MeerKAT in South Africa, the Australian Telescope Compact Array in Australia, and the Chandra X-Ray Observatory and the Neil Gehrels Swift Observatory in space.

“All the applications were immediately accepted.” “We applied for Director’s Discretionary Time on multiple telescopes, which is when you find something so unexpected, you can’t wait for the normal cycle of telescope proposals to observe it,” Cendes explains. Cendes and the team rushed to examine the event more closely. Radio data from the Very Large Array (VLA) in New Mexico showed that the black hole had mysteriously reanimated in June 2021. The team spotted the unusual outburst while revisiting tidal disruption events (TDEs) - when encroaching stars are spaghettified by black holes - that occurred over the last several years. The results, described this week in the Astrophysical Journal, may help scientists better understand black holes’ feeding behavior, which Cendes likens to “burping” after a meal. The team concludes that the black hole is now ejecting material traveling at half of the speed of light, but are unsure why the outflow was delayed by several years. “This caught us completely by surprise - no one has ever seen anything like this before,” says Yvette Cendes, a research associate at the Center for Astrophysics | Harvard & Smithsonian (CfA) and lead author of a new study analyzing the phenomenon. Though it may sound thrilling, the event did not come as a surprise to astronomers who occasionally witness these violent incidents while scanning the night sky.īut nearly three years after the massacre, the same black hole is lighting up the skies again - and it hasn’t swallowed anything new, scientists say. In October 2018, a small star was ripped to shreds when it wandered too close to a black hole in a galaxy located 665 million light years away from Earth.

Star turning into a black hole