Astronomers discover a brand-new cosmic object — the black hole star

MIT astronomers found MoM-BH*-1, an object 100 billion times brighter than any known star — a black hole 100,000 times the Sun's mass wrapped in a star-sized hydrogen cocoon and likely the seed of a supermassive black hole.

Astronomers have spotted something the universe has never shown them before: a "black hole star" — a black hole so swaddled in a cocoon of dense hydrogen that it radiates like an enormous star. The object, dubbed MoM-BH*-1, sits billions of light-years away in the constellation Cetus and formed roughly 660 million years after the Big Bang, according to MIT News.

The team, led by Dr. Rohan Naidu at MIT's Kavli Institute for Astrophysics and Space Research, was hunting for the earliest galaxies with the James Webb Space Telescope when a single dot stood out: intensely red, intensely bright, and unlike anything else in the archive. "The way its light is almost entirely red, and abruptly disappears below a certain wavelength, is so dramatic that there is no comparison among any known class of objects," Naidu told The Guardian.

The object glows 100 billion times brighter than any known star — far too much energy to come from nuclear fusion, the engine that powers every ordinary star. Simulations showed the closest match is an actively feeding black hole about 100,000 times the mass of the Sun, wrapped in a hydrogen envelope roughly the size of the solar system. That dense cocoon, thick enough to resemble a stellar atmosphere, blocks light below certain wavelengths and gives the object its eerie deep-red color.

If the interpretation holds, it solves a puzzle that has nagged astronomers since Webb opened its eyes: the mysterious "little red dots" that speckle nearly every deep-field image and then vanish from the modern universe. "Every little red dot is consistent with being a black hole star," Naidu said — with MoM-BH*-1 outshining its host galaxy so completely that astronomers are seeing "pure black hole star light."

The finding, published in Nature, points to something even bigger. Black hole stars may be the newborn phase of the supermassive black holes that sit at the center of nearly every galaxy today — including our own Milky Way. "They may be the nascent, swaddled phase that marks the beginning of almost every supermassive black hole's journey," Naidu said.

Sources: MIT News, The Guardian