620 light years apart, and due to collide: three black holes in one galaxy
What happened
Astronomers have found three supermassive black holes feeding at the same time inside a single galaxy in the very early universe. The galaxy is called J0148-4214. Its light has travelled more than 12.5 billion years to reach us, which means we are seeing it as it was roughly 1.2 billion years after the Big Bang. In astronomical terms that is very young indeed. Two of the black holes sit close to the galaxy’s centre, about 620 light years apart as seen from Earth. The third is further out, around 5,500 light years from the centre. Their estimated masses are strikingly different: about 80 million, 2 million, and 600,000 times the mass of the Sun. The whole galaxy holds only about 1.3 billion suns’ worth of stars, so the black holes make up a significant share of it. The work was led by the Max Planck Institute for Extraterrestrial Physics in Garching, heading an international team. They used the James Webb Space Telescope’s NIRSpec instrument in integral field spectroscopy mode, which captures a spectrum for every point in an image rather than just one. Even then, the telescope could not see the two central black holes as separate points. The team separated them using hydrogen emission patterns and a technique called spectro-astrometry. Hannah Übler, the MPE research group leader and lead author, said the discovery “is the first evidence of three active black holes in a single galaxy in the distant Universe”. The paper, “BlackTHUNDER: Evidence of three massive black holes in a z ∼ 5 galaxy”, was described in a release reported on 25 October 2026.
Why this matters
There is a long-standing puzzle in astronomy: the early universe contains black holes that look too big for their age. Black holes grow by swallowing gas, and there is a speed limit on that — the Eddington limit, the fastest rate basic growth models predict. Run the sums with that limit, start from a modest seed, and you struggle to reach the enormous masses we actually observe only a billion or so years after the Big Bang. This galaxy offers a possible way out. If black holes regularly form in groups and then merge, growth does not have to rely on steady feeding alone. Roberto Maiolino of the University of Cambridge, a co-author, suggested the results mean black hole merging “may be an additional, fast route for their rapid growth in the early Universe”. The two central black holes are expected to merge within a few hundred million years, which is soon by cosmic standards. There is a second, quieter point. Giovanni Mazzolari, the MPE researcher who is second author, noted that the JWST data allowed the team “not only to identify the three black holes” but to relate their masses and feeding rates to the galaxy around them. Without the spatial detail that integral field spectroscopy provides, astronomers would most likely have spotted just one. Which raises an obvious question about everything we have looked at with lesser instruments.
What the evidence actually says
This is good work, and it is worth being precise about its limits. The 620 light year separation is a projected distance — a measurement across the sky. The true separation in three dimensions could be larger, because we cannot easily tell how much of the gap runs towards or away from us. The masses and feeding rates are calculated, not measured directly. You cannot weigh a black hole. You infer its mass from how the gas around it behaves, using models. One of those calculations produced an interesting oddity. The smallest central black hole, at around 600,000 solar masses, appears to be feeding faster than the Eddington limit. The biggest one is not the hungriest. That is a genuine finding, and also a reminder that these are estimates drawn from models. The origin of the third, outlying black hole is unresolved. It might be a leftover from an earlier merger, kicked outwards by gravitational recoil. Or it might be migrating inwards. The team does not claim to know. The language throughout the research is appropriately careful. The merger timeline and the rapid-growth explanation are offered as suggestions. And it is worth noting that the striking image accompanying much of the coverage is an AI-generated visualisation, not a photograph, and is not to scale. No telescope sees a picture like that.
What to know
The James Webb Space Telescope has revealed three actively feeding supermassive black holes inside the galaxy J0148-4214, seen as it was about 1.2 billion years after the Big Bang, more than 12.5 billion light years away. Their estimated masses are about 80 million, 2 million and 600,000 times the mass of the Sun. Two sit near the centre, around 620 light years apart in projection, and are expected to merge within a few hundred million years. The third lies about 5,500 light years out, and its origin is unknown. The finding supports the idea that mergers gave early black holes a fast route to enormous size, helping explain why the early universe contains black holes that look too big for their age. The smallest central black hole appears to be feeding faster than standard models predict. Masses and feeding rates are calculated from models rather than measured directly, and the separation figure is a projected distance. The widely shared image of the system is an artist’s visualisation, not a photograph. Sources: Max Planck Institute for Extraterrestrial Physics, “Three giant black holes discovered in a galaxy from the dawn of time”, ScienceDaily, 25 October 2026, https://www.sciencedaily.com/releases/2026/10/261024222000.htm; Übler, H., et al., “BlackTHUNDER: Evidence of three massive black holes in a z ∼ 5 galaxy”, 2026, https://doi.org/10.1051/0004-6361/202557419 This article is for general information and does not replace advice from a doctor, pharmacist or other qualified healthcare professional.
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