Astronomers discover ‘black hole star,’ an entirely new type of cosmic object

Astronomers have identified a never-before-seen type of astrophysical object in the early universe: a "black hole star," a hybrid entity that looks like an enormous star but is powered by the gravitational engine of a black hole. The discovery, published Wednesday in the journal Nature, could reshape understanding of the mysterious "little red dots" that have appeared in nearly every deep-space image taken by NASA's James Webb Space Telescope.eurekalert+1

The object, named MoM-BH*-1, was found by a team led by Rohan Naidu, an astronomer at MIT's Kavli Institute for Astrophysics and Space Research. It appears as an extremely bright red spot dating to just a few hundred million years after the Big Bang. While it resembles a star spanning the size of the solar system, it radiates roughly 100 billion times more energy than any known star — output levels more consistent with a black hole.miragenews+1

"We think there is a central black hole that is 100,000 times as massive as the sun," Naidu said. "And around this black hole, there would be this very extended envelope of gas that looks like a star the size of the solar system".miragenews

A Serendipitous Find

The team was not looking for a new class of object. They were searching for the earliest galaxies as part of a survey they named "Mirage or Miracle," designed to determine whether extremely bright features in JWST images were genuine early galaxies or optical illusions. One feature — a very red, very bright dot — stood out immediately.popsci+1

Its light signature defied easy explanation. It exhibited the deepest "Balmer break" ever recorded, a spectral pattern typically associated with stellar atmospheres, but at a scale that ruled out ordinary stars. The light also contained almost no metals — only hydrogen and helium.eurekalert+1

Rewriting the Textbook

Simulations showed the dot could be explained by a massive accreting black hole wrapped in an extremely dense cocoon of hydrogen, producing light that mimics a stellar surface but at vastly greater energies. MKI Director Robert Simcoe, a co-author, said the team was surprised to find that "you can" produce such redness "if you have an extremely dense screen of hydrogen, so dense that it looks more like the surface of an enormous star than a wispy interstellar nebula".miragenews+1

The finding builds on earlier work. In June, a separate team led by Vasily Kokorev at the University of Texas at Austin published what NASA called the "strongest evidence yet" for the black hole star model, based on a detailed spectrum of a different little red dot. Naidu told Gizmodo that black hole stars may represent the "birth story of possibly every supermassive black hole," while the ubiquitous little red dots could each be a black hole star embedded within a larger galaxy.gizmodo+1

"Astronomers who study the early universe are so amped right now," Naidu said. "We are rewriting the textbooks and filling out new chapters for things that we didn't even know existed".gizmodo