Image Courtesy: MIT
Astronomers using the James Webb Space Telescope (JWST) may have identified an extraordinary object from the early universe that combines the appearance of a massive star with the power of a black hole. The object, called MoM-BH*-1, could represent a previously unknown type of astrophysical system, a black hole surrounded by an enormous envelope of dense hydrogen.
The discovery could also help explain one of JWST’s biggest early-universe mysteries: the population of extremely bright objects known as “little red dots.” These objects appeared only a few hundred million years after the Big Bang and seem to contain unexpectedly massive black holes. The new findings were reported in Nature.
MoM-BH*-1 initially stood out because of an unusually strong feature in its light called a Balmer break. This sharp drop in brightness at shorter wavelengths is associated with certain stellar atmospheres, but the break detected in this object is far stronger than researchers have observed in ordinary stars.
The object also appears to contain almost no elements heavier than helium. That suggests it formed before nearby generations of stars had exploded as supernovae and enriched their surroundings with heavier elements.
Researchers found that an extremely dense layer of hydrogen could potentially reproduce the object’s unusual color and spectrum. Instead of a thin cloud surrounding a black hole, the hydrogen would be so dense that it could resemble the outer atmosphere of an enormous star.
The object’s extraordinary brightness presents another challenge. Researchers estimate that the black hole at its center could be around 100,000 times more massive than the Sun. Its surrounding hydrogen envelope may extend to roughly five times the distance between Earth and Voyager 1.
Unlike a normal star, however, the object could not be powered by nuclear fusion. Its extreme luminosity is instead thought to come from material feeding the black hole, while the surrounding hydrogen gives the system a stellar appearance.
The researchers suggest that MoM-BH*-1 could represent an early stage of black hole growth known as super-Eddington feeding. If similar objects are responsible for JWST’s little red dots, they could provide a missing link in explaining how enormous black holes formed so quickly in the young universe.
The object is expected to eventually interact with a nearby galaxy, which could happen in roughly 100 million years. That merger could transform its appearance and potentially produce something resembling the unusually massive early quasars that have also puzzled astronomers.
The evidence remains a candidate rather than definitive proof of a new class of object. Further observations will be needed to determine whether MoM-BH*-1 truly represents a “black hole star” and whether similar objects are responsible for the little red dots.