Astronomers have discovered a new kind of massive explosion in space—so powerful that they outshine anything we’ve ever seen before.
These extraordinary bursts of energy, now called “extreme nuclear transients” or ENTs, happen when huge stars get too close to supermassive black holes and are ripped apart.
The discovery was made by a team from the University of Hawaiʻi’s Institute for Astronomy and published in the journal Science Advances.
What makes ENTs so unique is how incredibly bright and long-lasting they are. Normal cosmic explosions like supernovae—when stars blow up—are already mind-blowingly energetic.
But ENTs are on another level entirely.
One of them, named Gaia18cdj, gave off 25 times more energy than even the most powerful known supernova. To put that in perspective, ENTs can shine with the energy of 100 suns in just one year.
The story began when astronomer Jason Hinkle noticed something strange in data from the European Space Agency’s Gaia mission.
Gaia tracks changes in the brightness of stars and galaxies, and two unusual flares caught Hinkle’s eye.
These flares were smooth, bright, and lasted much longer than normal—something never seen before. This sparked years of follow-up observations using telescopes across the world, including Hawaiʻi’s Keck Observatory and UH’s ATLAS system.
More recently, a third similar flare was found by a different group using the Zwicky Transient Facility, confirming that ENTs are a real and rare type of cosmic event.
At first, the team thought these explosions might be supernovae, but the energy levels were far too high.
They also looked different from typical black hole activity, which is usually unpredictable and flickers over time. ENTs, on the other hand, have a smooth and steady glow that lasts for years.
The scientists believe the best explanation is that these events are caused when a giant star is torn apart by the gravity of a supermassive black hole. The star’s material slowly spirals into the black hole, creating a long-lasting and extremely bright flare.
ENTs are incredibly rare—at least 10 million times less common than supernovae—so finding them requires long-term sky surveys and a bit of luck. But they’re also incredibly valuable. Because they are so bright, we can see them even in very distant galaxies. That means they let scientists peek into the past and learn how black holes grew when the universe was much younger.
“These explosions aren’t just about the death of a star,” Hinkle said. “They also show us how the biggest black holes in the universe grow over time.”
As new telescopes like the Vera C. Rubin Observatory and NASA’s Roman Space Telescope come online, astronomers hope to discover many more of these rare cosmic events. Each one will help unlock new secrets about the mysterious forces shaping our universe.
Source: University of Hawaii at Manoa.
