Webb Telescope Finds Strongest Evidence Yet for a 'Black Hole Star' in the Early Universe

Astronomers using NASA's James Webb Space Telescope have found the strongest evidence yet for a "black hole star" — a rapidly feeding supermassive black hole shrouded in a dense cocoon of gas so thick that the whole object masquerades as a single, glowing star.

The object, catalogued as GLIMPSE-17775, belongs to a mysterious class of compact red sources Webb has been turning up across the early universe, nicknamed "little red dots." Since their discovery, these objects have puzzled scientists, who could not agree whether their reddish glow came from dense clusters of stars, dust-choked galaxies, or actively growing black holes. The new observations tilt the answer firmly toward a black hole wrapped in gas.

Using its NIRSpec multi-object spectrograph, Webb captured the deepest spectrum yet recorded for a little red dot, detecting more than 40 distinct spectral lines. Among them, researchers identified 16 separate iron lines — an "iron forest" — along with hydrogen, oxygen, helium and sulfur signatures, plus telltale patterns of electron scattering. Taken together, the data point to a layered envelope of partially ionized gas reprocessing light streaming from the immediate vicinity of an accreting black hole, exactly what the "black hole star" model predicts.

The light from GLIMPSE-17775 left the object when the universe was only about 1.8 billion years old, at a cosmological redshift of 3.5. The team's view was sharpened by gravitational lensing, in which the gravity of an intervening mass bends and magnifies the distant light — an effect researchers said boosted Webb's sensitivity to the equivalent of roughly 80 hours of telescope time. The findings, led by Vasily Kokorev of the University of Texas at Austin, were published in The Astrophysical Journal.

If the interpretation holds, black hole stars could help solve one of cosmology's nagging riddles: how supermassive black holes grew so large so quickly after the Big Bang. A black hole feeding behind a thick gas screen could pack on mass while hiding much of its energy from view, explaining why the early cosmos appears littered with these enigmatic red points of light. "Everything fits, nothing is broken, and I think that makes the puzzle that is our universe even better," Kokorev said.