Astronomers using the NASA/ESA/CSA James Webb Space Telescope have found an enormous black hole in the early Universe that appears to predate its own host galaxy, raising fresh questions about how the cosmos’ first supermassive monsters were born.
This Webb/NIRCam image shows the little red dot Abell2744-QSO1, magnified and triply imaged by galaxy cluster Abell 2744. Image credit: NASA / ESA / CSA / Lukas Furtak, Ben-Gurion University / Alyssa Pagan, STScI.
Abell 2744-QSO1 (QSO1 for short) is a prototypical ‘little red dot’ that existed just 700 million years after the Big Bang.
Although QSO1 is only 1,300 light-years across, and its light has been traveling for more than 13 billion years, it is easier to study than most other little red dots because it is gravitationally lensed by the galaxy cluster Abell 2744.
QSO1 is both magnified and triply imaged, appearing in three different locations in the sky.
“This is a remarkable finding,” said Dr. Roberto Maiolino, an astronomer at the University of Cambridge.
“It’s a paradigm shift, a total revisiting of the classical scenarios of how black holes form and grow.”
Initial studies of QSO1 revealed compelling evidence that it may be little more than a cloud of glowing hydrogen and helium gas circling a supermassive black hole estimated at 40 million times the mass of the Sun.
But as with other early black holes discovered by Webb, there was uncertainty about whether it really was that massive.
“Before now, all of the mass measurements of black holes in the early Universe have been indirect, based on assumptions from what we know about them in the local Universe,” said Dr. Francesco D’Eugenio, also from the University of Cambridge.
“We didn’t know if those assumptions really apply to the distant Universe.”
The astronomers used the integral field unit (IFU) on Webb’s NIRSpec instrument to map motions of hydrogen gas surrounding the black hole.
When they plotted the rotation velocity as a function of distance from the center, they found that the gas has Keplerian motion: it orbits a central point in the same way that planets in our Solar System orbit the Sun.
“This is important because it tells us that most of the mass of QSO1 is concentrated in the black hole at the center,” said University of Cambridge graduate student Ignas Juodžbalis.
“If the mass were more distributed, as it would be if there were a lot of stars, the gas would not have this perfect Keplerian rotation.”
Since Keplerian motion is governed by simple laws of gravity, the researchers were able to use the gas velocity measurements to calculate the black hole mass directly, a feat that had not previously been possible.
They found that not only is the black hole immense (roughly 50 million solar masses), it makes up — at minimum — an astonishing two-thirds of QSO1’s total mass.
This proportion is thousands of times greater than in nearby galaxies, where supermassive black holes make up only a tiny fraction of the host galaxy’s total mass.
The IFU composition maps supported these results, showing that the gas throughout QSO1 is almost entirely hydrogen and helium, with very little of the heavier elements like oxygen that would be expected in a galaxy rich with stars and stellar debris.
With a metallicity less than 0.5% of the Sun, QSO1 is one of the most pristine galactic environments ever measured.
“This is a phenomenal result,” said Dr. Cosimo Marconcini, an astronomer at the University of Florence.
“It is the first direct measurement of a black hole mass within the first billion years after the Big Bang, and it is consistent with the previous measurements.”
The outsized mass of QSO1 relative to its host galaxy suggests that it can’t have formed gradually from much smaller, stellar-mass black holes merging and feeding
“It seems that we have found a black hole that does not have a substantial host galaxy and that has predated stellar processes,” Juodžbalis said.
“This is very exciting because it is evidence for primordial black holes or direct collapse black holes, which have been theorized but not confirmed.”
“Whether QSO1’s black hole evolved from a heavy seed that formed within the first second of the Big Bang or somewhat later from the collapse of a giant cloud of gas, it was almost certainly born big, and may be in the early stages of building a galaxy around it.”
The results appear in two papers in the journal Nature and the Monthly Notices of the Royal Astronomical Society.
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I. Juodžbalis et al. 2026. A direct black-hole mass measurement in a little red dot at high redshift. Nature 653, 1017-1021; doi: 10.1038/s41586-026-10579-4
Roberto Maiolino et al. 2026. A black hole in a near pristine galaxy 700 Myr after the Big Bang. MNRAS 548 (1): staf2109; doi: 10.1093/mnras/staf2109
