Webb telescope spots new type of object: a ‘black hole star’

Astronomers using NASA's James Webb Space Telescope have identified what appears to be an entirely new type of cosmic object: a "black hole star" that combines traits of both a massive black hole and a giant star. The discovery, published in the journal Nature, could reshape understanding of how the universe's earliest structures formed.

A New Class of Object

The object, named MoM-BH*-1, was detected in the early universe just 660 million years after the Big Bang. It appears as an intensely bright red dot in JWST images, roughly the size of our Solar System, yet emitting about 100 billion times more energy than any ordinary star — far exceeding what nuclear fusion could produce.notebookcheck+1

"We think there is a central black hole that is 100,000 times as massive as the sun," said lead author Rohan Naidu, a NASA Hubble Fellow and Pappalardo Fellow at MIT's Kavli Institute for Astrophysics and Space Research. "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. It's huge."phys

The team found the object during the "Mirage or Miracle" (MoM) survey, which was searching for some of the universe's earliest galaxies. Spectroscopic analysis revealed the deepest Balmer break ever measured at any redshift, a near-total absence of elements heavier than hydrogen and helium, and brightness that ruled out conventional stellar explanations.dailygalaxy+1

A Black Hole Powering a Star-Like Shell

Computer simulations showed that only a model combining a massive accreting black hole with an enormous hydrogen gas envelope could reproduce MoM-BH*-1's extraordinary brightness and spectral features. Unlike a normal star powered by fusion, this object draws its energy from matter falling into the central black hole, while the surrounding gas creates its star-like appearance.notebookcheck+1

The object may also have brightened by roughly 30 percent over two months of observations, consistent with a growing black hole feeding on surrounding material.dailygalaxy

Solving the Mystery of the Little Red Dots

The discovery could help explain one of the biggest puzzles of the JWST era: the numerous "little red dots" appearing throughout deep-space images of the early universe that seem to have vanished in more recent cosmic periods. The researchers suspect many of these enigmatic sources may be black hole stars embedded within early galaxies.phys+1

"Every little red dot is consistent with being a black hole star, embedded in a generic early galaxy," Naidu said. "But what is special about MoM-BH*-1 is, the black hole star is essentially completely outshining its surrounding host galaxy, such that we're seeing pure black hole star light."phys