MIT astronomers and their collaborators have identified what appears to be an entirely new type of astrophysical object: a black hole star. Using NASA's James Webb Space Telescope, a team led by Rohan Naidu, with MIT co-authors Robert Simcoe and Wendy Sun, reported the object, designated MoM-BH*-1, in Nature. It was spotted during the group's Mirage or Miracle survey of the early universe, in light emitted when the cosmos was only a few hundred million years old.
The object's spectrum shows an unusually deep Balmer break and almost no elements heavier than hydrogen and helium, a combination that defies standard galaxy or star classifications. Simulations that best match the data describe a black hole of roughly 100,000 solar masses accreting inside a dense hydrogen envelope about the size of the solar system, shining with a luminosity far too great for nuclear fusion to supply.
The discovery carries weight well beyond a single curiosity. The authors propose that black hole stars may account for the little red dots, the compact crimson sources that pepper deep JWST images and have resisted explanation. If so, these hybrid objects would offer a window on to one of cosmology's hardest questions: how supermassive black holes grew so large, so early in cosmic history.