Astronomers Identify Unprecedented “Black Hole Star” in Early Universe

A team of astronomers from MIT and other institutions has discovered an exceptionally bright red object dating back to the early universe, only a few hundred million years after the Big Bang. Dubbed a “black hole star,” this unprecedented cosmic entity produces approximately 100 billion times more energy than any known star, suggesting a new type of astrophysical source.

Published on August 12 in Nature, the study analyzes observations made with NASA’s James Webb Space Telescope (JWST). The object appears massive, resembling a star with dimensions comparable to our solar system. Instead of relying on nuclear fusion, it may consist of a dense cloud of gas energized by a central black hole estimated to be 100,000 times the mass of the Sun.

Investigating an Early Universe Mystery

Lead author Rohan Naidu, a NASA Hubble Fellow and Pappalardo Fellow at MIT, states, “Our picture of this object is evolving very rapidly.” The discovery could help elucidate the mysterious “little red dots” frequently seen in JWST’s deep-space images, which have puzzled astronomers. “These little red dots seem to be everywhere in the early universe but essentially disappear by the present day,” Naidu adds.

The researchers were initially focused on identifying distant, early galaxies through a survey named “Mirage or Miracle” (MoM). While searching for potential targets, they identified this anomalously bright source, which displayed characteristics inconsistent with being surrounded by conventional dust.

Rather than the expected red hue caused by cosmic dust, the light from the object revealed a unique pattern. A profound drop in light known as a “Balmer break” indicated that the object is not an ordinary star. Naidu described it as “the deepest break we have ever observed,” prompting questions about whether this represented a new kind of stellar atmosphere.

Interestingly, the object showed mostly hydrogen and helium, with almost no evidence of other metals or elements. This unusual composition deepens the intrigue surrounding its formation and energy source.

Initial Simulations and Theoretical Models

To explore possible explanations, researchers ran simulations of different astrophysical scenarios. “We started to ask: Could you make something that red using just hydrogen, without any dust?” said Robert Simcoe, an MIT coauthor. “To our surprise, it turns out you can, if you have an extremely dense screen of hydrogen.”

The simulations suggested that the extraordinary brightness of the object stems from a central black hole hidden within an envelope of dense hydrogen. After adjusting the properties of the black hole in their models, the researchers concluded this object represents a new class of astronomical phenomena.

The researchers have named the object MoM-BH*-1, suggesting it could be the first example of a wider population of similar entities.

The Implications for Future Observations

As the team continues its research, they speculate that black hole stars may explain many of the other little red dots detected in JWST images. Naidu notes, “Every little red dot is consistent with being a black hole star, embedded in a generic early galaxy.” The extraordinary nature of MoM-BH*-1, however, lies in its ability to outshine its surrounding host galaxy, revealing the pure light of a black hole star for the first time.

This groundbreaking discovery opens new avenues for understanding the early universe and may serve as a pivotal clue to one of the most debated mysteries emerging from the JWST era, highlighting a type of cosmic object that has never before been directly observed.

This research was supported, in part, by the MIT Department of Physics, NASA, and the Space Telescope Science Institute.