“Dark stars” could help solve three seemingly disconnected mysteries that emerged at cosmic dawn — mysteries recently discovered by the James Webb Space Telescope. The puzzles include:

• the surprising overabundance of supermassive black holes in the early universe,

• the unexpected existence of “blue‑monster” galaxies, and

• the so‑called “little red dots” – a newly identified class of compact objects that appear to have vanished before the universe was about 2 billion years old.

What are dark stars?

Dark stars are hypothetical objects proposed to have existed in the early universe. Unlike normal stars, which are powered by nuclear fusion, dark stars would have been powered by the annihilation of dark‑matter particles. The term “dark” refers to this energy source; despite the name, they would have been extremely luminous.

If they existed, dark stars could form before ordinary stars. When the ultradense cores of dark matter are exhausted, the stars are thought to collapse, leaving behind massive “seeds” for supermassive black holes. These seeds would be far more massive than black holes formed from the collapse of even the most massive ordinary stars, allowing supermassive black holes to appear much earlier than standard merger‑driven growth models predict.

Connecting the dots

• Supermassive black holes: The early appearance of massive black holes (detected by JWST less than a billion years after the Big Bang) could be explained by the rapid growth of dark‑star seeds.

• Blue‑monster galaxies: JWST has also uncovered ultra‑compact, extremely bright, dust‑poor galaxies—dubbed “blue monsters”—that no cosmological simulation had predicted. The team behind the dark‑star hypothesis suggests these objects may not be galaxies at all, but luminous dark stars whose brilliance makes them appear as compact galaxies only a few hundred light‑years across.

• Little red dots: These faint, compact sources emit weakly in the ultraviolet and show no X‑ray emission. If they are the remnants of dark stars that have exhausted their dark‑matter fuel, the resulting black holes could remain surrounded by layers of stellar material. This material would partially obscure ultraviolet light and completely block X‑rays, matching the observed properties of the little red dots.

Current status

Dark stars remain a theoretical construct, but some emerging observational hints are consistent with their existence. The research presented in a December 2025 paper in Astrophysics and Cosmology at High Z offers a unified mechanism that could simultaneously address the three early‑universe puzzles.

“Supermassive dark stars can offer a solution to several pressing puzzles in astronomy and astrophysics, as discussed in depth in this paper,” the authors concluded. “To our knowledge, there is no other mechanism that can achieve this simultaneously.”

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About the author

Robert Lea is a science journalist in the U.K. whose articles have appeared in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. He holds a B.Sc. in physics and astronomy from the Open University. Follow him on Twitter @sciencef1rst.