Astronomers have captured the most powerful and farthest black hole flare ever recorded—a cosmic light show so bright it outshined 10 trillion suns.
The flare, described in Nature Astronomy, is believed to have been caused by a gigantic star wandering too close to a supermassive black hole, which ripped the star apart and slowly devoured it.
The discovery was made using the Zwicky Transient Facility (ZTF) at Caltech’s Palomar Observatory and the Catalina Real-Time Transient Survey, both supported by the U.S. National Science Foundation (NSF).
The flare, officially named J2245+3743, first appeared in 2018 and quickly brightened by a factor of 40 within months. It became 30 times more luminous than any black hole flare ever seen, releasing energy equivalent to the total mass of the Sun converted entirely into light.
“This is unlike any active galactic nucleus we’ve ever seen,” said Matthew Graham, lead author of the study and a research professor of astronomy at Caltech.
“Its energy output and distance make it truly extraordinary.”
The black hole behind the flare sits in the heart of an active galactic nucleus (AGN)—a galaxy whose central black hole feeds on gas, dust, and stars.
This particular black hole weighs about 500 million times more than the Sun and lies roughly 10 billion light-years away. Because light takes time to travel, astronomers are seeing the event as it occurred when the universe was still young.
As they continue to observe the flare, astronomers note that it is fading slowly. But time behaves differently in the distant universe.
“It’s a phenomenon called cosmological time dilation,” Graham explained. “Because space is expanding, time for the flare runs slower there. What we see happening over seven years on Earth is only about two years in that distant galaxy. It’s like watching the event in slow motion.”
After exploring many possible explanations, the team concluded that the flare was likely caused by a tidal disruption event (TDE)—a cosmic catastrophe that occurs when a star ventures too close to a black hole. The black hole’s immense gravity stretches and tears the star apart, creating a violent burst of energy as the remains spiral inward.
“The black hole is essentially eating the star,” Graham said. “In this case, we’re watching a star that’s only halfway down the whale’s throat—it’s not fully gone yet.”
Based on the brightness and duration of the flare, scientists estimate that the doomed star had at least 30 times the mass of our Sun, making it one of the largest stars ever observed to fall victim to a black hole. For comparison, the previous record-holder for such an event—nicknamed “Scary Barbie”—was 30 times weaker and involved a much smaller star, only a few times the Sun’s mass.
What makes this discovery even more remarkable is that it occurred inside an AGN, a type of black hole system already surrounded by a swirling disk of gas and dust. Most TDEs are detected around quieter black holes, but this flare was so powerful that it outshone the AGN’s normal activity.
At first, the object didn’t stand out. In 2018, early spectral data from the Palomar Observatory showed nothing unusual. But by 2023, as the flare continued, observations from Hawaii’s W. M. Keck Observatory revealed the event’s extreme brightness. Further data from NASA’s Wide-field Infrared Survey Explorer (WISE) confirmed that the light wasn’t just beamed in our direction—it was radiating in all directions, proving its truly enormous power.
“If you converted the entire Sun into energy using Einstein’s formula E = mc², that’s the kind of energy this flare has released since we began observing it,” said K. E. Saavik Ford, co-author and professor at the City University of New York and the American Museum of Natural History.
The discovery hints that such massive “black hole meals” may be more common than previously thought. Future sky surveys, including those from the upcoming Vera C. Rubin Observatory, could uncover more of these cosmic feasts in distant galaxies.
“We never would have found this rare event without long-term sky surveys like ZTF,” Graham said. “By continuously monitoring the sky, we can see how these extraordinary events begin, evolve, and fade. It’s like watching the universe tell its own story—one star at a time.”
