When a Black Hole Ate a Star the Size of 30 Suns
Astronomers just found the brightest black hole flare ever — from a feast that began 10 billion years ago
A black hole is one of the strangest things in the universe — at least among the things we know about.
If Shakespeare had studied astrophysics, he might have said, “There are weirder things in the cosmos than are dreamt of in your philosophy.”
Even among black holes, some are stranger than others. Thanks in part to the research done for Christopher Nolan’s Interstellar, we learned they can spin, stay relatively quiet or be very raucous, and bend light so violently that their glowing disks seem to fold over and wrap around them like a hellish halo.
And now — though “now” doesn’t really apply in cosmic time — astronomers have found evidence of something that happened about 10 billion years ago, before Earth even existed. Back then, galaxies were smaller, further apart, and a supermassive black hole was about to put on a light show brighter than anything we’ve ever seen.
A new study in Nature Astronomy, led by Matthew Graham of Caltech, describes how a black hole ripped apart and swallowed a giant star, releasing the energy of roughly 10 trillion suns.
Black holes consume stars all the time, Graham says, but this flare was thirty times brighter than any ever recorded.
Part of that came down to scale. The doomed star was at least 30 times more massive than our Sun. The black hole itself — and the swirling disk around it — weighs in at about 500 million solar masses.
The outburst has been blazing for more than seven years and may still be going.
Astronomers first spotted the flare in 2018 during a sky survey using three ground-based telescopes. At first it was logged as just another unusually bright object. Follow-up observations didn’t yield much, so it was set aside until 2023, when Graham’s team took a second look.
That’s when the shock set in.
“Suddenly it was, ‘Oh — this is actually quite far away,’” Graham said. “And if it’s that far and this bright, how much energy is being put out? This is something unusual and very interesting.”
So even in a universe filled with mysteries, this one stands out. A reminder that as bizarre as black holes already seem, there are far stranger things still waiting in the dark.