Dark Stars May Explain Universe’s Earliest Black Holes

New evidence from the James Webb Space Telescope (JWST) is providing the most convincing indications to date that dark stars, massive celestial objects fueled by dark matter, existed in the early universe. Such stars potentially explain the rapid development of supermassive black holes.

Hints of Dark Stars Emerge

An examination of several extremely distant objects reveals spectra and shapes aligning with dark star simulations rather than those of typical stars powered by nuclear fusion, according to a new analysis. These potential dark stars are located over 13 billion light-years away; their light originated when the cosmos was just a few hundred million years old.

The idea of dark stars was initially proposed in 2007 by **Katherine Freese** and her colleagues at the University of Texas at Austin.

Dark Matter’s Role

Dark matter constitutes approximately 85% of the universe’s mass, yet it interacts with ordinary matter only through gravity. Despite extensive searches, direct detection of dark matter particles has remained elusive. Still, its gravitational influence is evident in the structure of galaxies and galaxy clusters.

**Freese** theorized that, within early gas halos, self-annihilating dark matter particles could produce heat at a rate exceeding the gas’s ability to cool. This process would lead to the formation of stars with masses millions of times that of our sun, but without the initiation of nuclear fusion. Upon depletion of the local dark matter supply, these stars would collapse, potentially giving rise to black holes massive enough to become the seeds of the earliest quasars.

JWST’s Observations

The infrared capabilities of the James Webb Space Telescope are well-suited to observe these ancient, inflated stars. Indeed, its instruments have already detected numerous unexpectedly bright objects from the Cosmic Dawn era. The telescope is now probing the re-ionization epoch to identify even more candidate dark stars. Data suggest many early galaxies cleared away the fog of hydrogen gas far earlier than expected (Space.com).

Studying objects such as JADES‑GS‑z11‑0 and JADES‑GS‑z13‑0, **Freese**’s team suggests that a single dark star could explain the characteristics of each, rather than attributing them to entire infant galaxies. According to **Freese**, “If it’s real, then I don’t know how else you’d explain it other than with a dark star.” Further supporting this hypothesis is a possible absorption dip at a specific wavelength, indicative of ionized helium, which is uniquely predicted for dark star atmospheres.

Skepticism Remains

However, not everyone agrees with the dark star interpretation. **Daniel Whalen** at the University of Portsmouth, who studies the formation of massive stars without dark matter, remains unconvinced. **Whalen** states that researchers “ignore an entire body of literature on the formation of supermassive primordial stars, some of which could give signatures very similar to the signatures that they show.”

**Whalen** proposes that rapid gas accretion could independently inflate stars to enormous sizes, and that current Webb telescope data cannot differentiate between these hot, massive stars and the cooler, more diffuse dark stars proposed by **Freese**.

Implications for Early Black Holes

The existence or non-existence of dark stars has major implications. JWST and Chandra recently discovered a black hole in galaxy UHZ‑1, which has a mass close to 10 billion times the mass of the sun. This black hole existed just 500 million years post-Big Bang. It is difficult to explain how such a massive black hole could form so quickly, using traditional models.

The rapid collapse of a dark star could provide a shortcut to creating the seed for such a black hole. While supermassive primordial stars represent another possibility, they depend on very specific conditions that may not be sufficiently common to account for the observed number of early quasars.

Future Research

Moving forward, researchers will seek to confirm the helium absorption signal and investigate whether metals are present within these systems, which would challenge current dark star theories. Additional Webb observations and surveys from the Roman Space Telescope could identify hundreds of similar objects. For now, dark stars remain a compelling, albeit unconfirmed, explanation for various enigmas of the early universe.

The study is published in the journal Proceedings of the National Academy of Sciences.