Lowest surface temperatureabout 4 000 K (3 730 °C)below that, the envelope disperses[2]
Leaves behindblack holes of 1 000–10 000 Sunspossible seeds of supermassive black holes[2]
Confirmednot yetJWST 'black hole stars' are candidates[1]
About the image. Drawn as a huge glowing orange envelope of gas with a bright core, inside which a small black hole and its disc are feeding. No quasi-star has been confirmed; its appearance is imagined from models.
Supermassive black holes billions of times the Sun’s mass already existed less than a billion years after the Big Bang. Growing them that fast from the remnants of ordinary stars is difficult. One proposed shortcut is a strange kind of object that may have existed only in the early universe: the quasi-star.
A star powered by a black hole
In the early universe, enormous clouds of almost pure hydrogen and helium could collapse directly into a single giant object. According to the model developed by Mitchell Begelman and colleagues between 2006 and 2008, its core would collapse into a black hole, but the vast outer envelope of gas would remain, wrapped around it.
That object would shine like a star, but not because of fusion. Its energy would come from the black hole feeding on the gas around it. The heat released would hold the envelope up, and the envelope in turn would feed the black hole far faster than a naked black hole could ever eat. A quasi-star might be as bright as a small galaxy.
Short-lived
It could not last. As the black hole grows, the envelope expands and its surface cools. When it falls to about 4 000 K (3 730 °C), the models show, the envelope can no longer hold together and drifts away. A quasi-star would live only about 7 to 10 million years, leaving behind a black hole of perhaps 1 000 to 10 000 solar masses: a head start towards becoming supermassive.
Black hole stars?
In its first years of observations the James Webb Space Telescope found many “little red dots”: compact, red objects in the early universe that did not fit any expected category. In 2025 two teams studied extreme examples, one nicknamed The Cliff and another called MoM-BH*-1, and argued that their light is best explained by a black hole wrapped in a dense shroud of gas, which they called a “black hole star”. Some theorists have suggested these may be late-stage quasi-stars. Whether that interpretation holds is still being debated, and no quasi-star has been confirmed.
Gallery
A huge glowing orange sphere with swirling layers around a bright ring and a dark centre, an impression of a quasi-star with a black hole at its heart. AI-generated painting.An enormous red-orange ball of glowing gas beside dark billowing clouds, an impression of a hypothetical quasi-star in the early universe. AI-generated painting.Quasi-star, 3D artist's impression, rendered from the interactive model.Quasi-star, 3D artist's impression, from another angle, rendered from the interactive model.Quasi-star, 3D artist's impression, close-up, rendered from the interactive model.
Timeline
2006Begelman, Volonteri and Rees describe direct collapse in early galaxies.
2008Begelman, Rossi and Armitage model quasi-stars.
2025JWST 'little red dots' are proposed as black hole stars.
Questions people ask
Do quasi-stars exist?
None has been confirmed. Some JWST objects in the early universe may be related to them.
How is a quasi-star different from a normal star?
Its light would come from a black hole feeding inside it, not from nuclear fusion.