Supermassive black hole spews gas at record speeds, upending mass estimates

Gaby Clark
scientific editor

Robert Egan
associate editor

One of the most powerful black holes in the universe is belching out gas at speeds of up to 10,000 kilometers per second, making its estimated mass more than 10 times lower than first thought.
The monster black hole, known as SMSS J052915.80-435152.0 (or simply J0529), was first discovered in 2024 by Associate Professor Christian Wolf and his team at The Australian National University (ANU).
Using brand-new powerful optical equipment at the European Southern Observatory in Chile, they have now been able to magnify the black hole's light and get a closer look at the gas swirling around it. The paper is on the arXiv preprint server.
"Despite the quasar's extreme luminosity, the black hole at its heart was found to have a mass equal to 'only' around one billion suns," Associate Professor Wolf said.
"Instead of rapidly rotating as previously presumed, this black hole is belching up the gas it's feeding on. The gas is being blown away by the ferocious density of light—this is the brightest object in the universe we know of."
The black hole is more than 12 billion light-years away, making it challenging to study its inner structure—until now.
"This points at a solution to the question of where all these huge black holes in the universe are coming from," Associate Professor Wolf said.
"While the rate at which they grow is still too fast to be explained easily, the re-weighing of this object and ones like it means that supermassive black holes may well originate from collapsing stars in the early stages of the universe, which had until recently seemed impossible."
Separately, Professor Michael Ireland from ANU is helping ESO advance its interferometry technology even further, meaning that it can soon be used to look at many more objects across the sky in even greater detail.
"My research area is the birth of planets around young stars, which will be revolutionized by the new technology at ESO. In the near future, our own creation story will only get more colorful," Professor Ireland said.
More information: GRAVITY+ Collaboration et al, Spatially resolved broad line region in a quasar at z=4: Dynamical black hole mass and prominent outflow, arXiv (2025).
Journal information: arXiv
Provided by Australian National University