On August 12, 2026, *Nature* published work by a research team from MIT, the Institute of Science and Technology Austria, and other institutions: using the James Webb Space Telescope (JWST), they captured an unprecedented astrophysical source in the extremely early universe, when the cosmos was only about 660 million years old — **MoM-BH*-1. Its scale is only about the size of the Solar System, yet its energy output reaches roughly 100 billion times the physical upper limit of ordinary stars. At its center is a black hole of about 100,000 solar masses, wrapped in a dense hydrogen envelope forming a 'giant stellar surface.' The team named it a 'Black Hole Star.' The discovery may both solve the 'Little Red Dots' mystery that has puzzled astronomers since JWST launched, and offer a new physical mechanism for the rapid formation of early supermassive black holes.
1. A Discovery Not on the Plan
The team was originally conducting the 'Mirage or Miracle' (MoM)** survey, using JWST to search for the most distant, oldest galaxies. Browsing deep-field images, they spotted an unusually bright, extremely red point of light — Solar System-sized, yet far brighter than any known stellar source.
The classic explanation for red distant objects is dust, which absorbs shorter wavelengths. But MoM-BH*-1's spectrum did not fit this explanation.
The most striking feature is an abnormally strong Balmer break — a steep 'cliff' in the spectrum where hydrogen absorbs radiation near a specific wavelength, typical of stellar atmospheres and dense hydrogen environments. The problem: MoM-BH*-1's Balmer break is anomalously strong, measured at about 7.7, while the theoretical ceiling for typical dust-free stellar populations is about 3; even a population dominated by A-type stars with strong Balmer breaks can hardly reach this level. So it is not an ordinary star.
Moreover, its spectrum shows almost no metal features — mainly hydrogen and helium — indicating an early stage of cosmic chemical evolution.
2. The Model Revealed What It Is
The researchers used a three-step simulation approach:
1. Can hydrogen explain the red color? Yes — but only with an extremely dense hydrogen medium, so dense it looks like the surface of a giant star rather than a diffuse nebula. This dense gas explains the unique Balmer break and the hydrogen/helium-only spectrum. 2. Can it explain the extreme luminosity? No — fusion powers all known stars and has a physical mass limit. MoM-BH*-1's output is ~100 billion times that limit; fusion cannot suffice. 3. Introduce a black hole as the engine: Feeding an actively accreting black hole into the hydrogen-envelope simulations and tuning parameters, the best-matching model is a central black hole of ~100,000 solar masses surrounded by dense hydrogen and helium gas nearly Solar System-sized. Accretion powers the system; the outer gas makes it look like a giant star.
Lead author Rohan Naidu (MIT / University of Hawaii) said: "The Balmer break we observe in this object is the strongest of any object ever found, ruling out ordinary stars as the energy source. This led us to wonder whether we are seeing a completely new kind of 'stellar atmosphere' — just at an unimaginable scale."
The name MoM-BH*-1 — 'black hole star number one' — hints that more such objects may exist.
3. Why This May Solve the 'Little Red Dots' Mystery
Since JWST began science operations in 2022, astronomers have noticed a class of mysterious objects recurring in deep images: compact, bright, and reddish. They appear throughout the early universe, but their density declines rapidly with time and they are nearly absent in the local universe.
Their identity has long been debated: high-redshift galaxies? Dust-obscured AGN? A new star-formation mode? No consensus exists.
The key point about MoM-BH*-1: placing similar objects in early galaxies would produce spectra highly resembling the Little Red Dots. Naidu offers a working hypothesis: "Every Little Red Dot could be a black hole star embedded within a typical early galaxy — the special thing about MoM-BH*-1 is that its light completely outshines the host galaxy, so we see purely the black hole star's light."
This means that at least some Little Red Dots may not be ordinary star-forming galaxies but rapidly accreting black holes wrapped in dense hydrogen shells — objects disguised as stars by their gas envelopes.
4. Another Path to Supermassive Black Hole Origins
The deeper significance concerns the origin of supermassive black holes (SMBHs), which reach millions to billions of solar masses at the centers of massive galaxies. But why did such huge black holes already exist within a few hundred million years of the Big Bang?
Under existing theory, black holes form from dying massive stars and must grow to 10⁵–10⁹ solar masses through prolonged mergers and accretion. Yet JWST has observed SMBH signatures in multiple objects at z > 7 (universe younger than 800 million years) — they seemingly lacked time to grow that large.
The black hole star hypothesis provides a transitional mechanism — a special stage of rapid early black hole growth, protected by a massive gas envelope. Naidu: "For decades we've expected something spectacular to have happened in the primordial universe. Black hole stars may be that spectacular thing."
The team's next step is clear: use JWST to examine other red-dot systems beyond MoM-BH*-1 and test whether their spectra fit the black hole star model. If so, this new class could expand from a single example to a countable astronomical population within a few years.
5. Three Things to Watch in Future JWST Observations
First: revisit known Little Red Dots. The MoM survey and follow-ups (such as CEERS and JADES) have accumulated hundreds of candidates. NIRSpec spectroscopic verification of each is the most direct test over the next 6–12 months.
Second: measure metallicity evolution. Black hole stars predict 'almost only hydrogen and helium.' Observing increased metals in later candidates would support an evolutionary path of 'black hole star + subsequent chemical enrichment.'
Third: look at the gas with ALMA. JWST probes the hydrogen envelope's spectral profile, while ALMA at millimeter/submillimeter wavelengths can directly detect hydrogen, helium, and molecular gas dynamics, pinning down the 'stellar surface' physical parameters.
What makes MoM-BH*-1 most fascinating is how it captured an object 'predicted by theory decades ago' in a case of observation finally catching up with theory. Black hole stars were a pen-and-paper exercise in relativistic astrophysics 50 years ago; now JWST has delivered one to us from 13 billion light-years away — one of the most direct payoffs since the telescope launched.
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Sources
- Paper DOI: 10.1038/s41586-026-10846-4