Brightest Ever: Black Hole Flare Shines Like 10 Trillion Suns From 10 Billion Light-Years Away

Record-breaking flare: a supermassive black hole lights up the distant universe

Scientists report the most powerful and most distant black hole flare yet observed: a supermassive black hole appears to have violently torn apart an enormous star, producing a flare with the brightness equivalent to about 10 trillion suns. The outburst was detected from roughly 10 billion light-years away and is described in a new study published in Nature Astronomy.

'This is really a one-in-a-million object,' said Matthew Graham, a research professor of astronomy at the California Institute of Technology and the study's lead author.

Graham and colleagues say the event most closely matches a powerful black hole flare, likely a tidal disruption event (TDE) in which a star is shredded by the black hole's gravity. While they favor this interpretation based on the flare's extraordinary intensity and long duration, follow-up observations are needed to confirm the details.

At its peak the outburst was around 30 times more luminous than any previously recorded black hole flare. Part of that extreme brightness stems from the sizes of the objects involved: the doomed star is estimated to have been at least 30 times the mass of the Sun, while the black hole and its surrounding accretion disk are estimated at roughly 500 million solar masses.

The flare was first flagged in 2018 during a wide-area sky survey using three ground-based telescopes. Initially logged as a particularly bright object, it yielded little usable follow-up data at the time and was largely set aside until 2023, when Graham and his team reexamined intriguing candidates from the survey and realized the source was much farther — and much more energetic — than they first thought.

Graham suggested the star may have been nudged off its orbit by interactions with other objects — akin to 'cosmic bumper cars' — sending it into a close, destructive encounter with the black hole.

Why this matters

The discovery helps reshape astronomers' view of supermassive black hole environments. Far from being quiet, slowly feeding objects, many galactic centers appear to be dynamically active, producing dramatic and rare events that offer unique windows into extreme physics. The flare has been fading over time but is expected to remain observable with ground-based telescopes for a few more years, giving astronomers additional opportunity for study.

Key facts: detected ~2018; reexamined in 2023; still ongoing for >7 years; distance ~10 billion light-years; peak brightness ~10 trillion suns; star ~30 solar masses; black hole ~500 million solar masses; peak luminosity ~30× that of any prior black hole flare.