New research suggests that the intriguing “little red dots” observed in the early universe might be a new kind of cosmic object: black hole stars. If true, this could shed light on how supermassive black holes grew to enormous sizes when the universe was still young, less than a billion years after the Big Bang.
These little red dots are among the most captivating celestial formations seen by the James Webb Space Telescope (JWST). Scientists believe they might be early galaxies existing just 700 million years post-Big Bang. However, these objects don’t behave like any galaxies familiar to us in today’s universe, which is 13.8 billion years old.
Instead of ancient, well-formed galaxies, researchers like Joel Leja from Penn State University propose that these dots could be vast structures of hot, dense gas resembling star atmospheres. Yet, they aren’t powered like traditional stars. Instead, they’re thought to be driven by supermassive black holes ravenously consuming nearby matter.
“We thought these were little galaxies filled with stars, but it turns out they might be like a gigantic, very cold star,” Leja explained. This new perspective can help reconcile some complex theories about galaxy formation.
Some experts say that the brightness and mass of these dots challenge current galaxy formation models. Bingjie Wang from Princeton University noted, “If this interpretation holds, it implies that stars formed in ways we’ve never observed before.” The night sky of such a galaxy would be unbelievably bright if it were made up of regular stars.
Initially, scientists believed these red dots were ancient galaxies. As they analyzed spectra from these objects, they stumbled upon a significant discovery: an early object named “the Cliff,” located about 12 billion light years away. The Cliff’s extreme properties forced researchers to rethink their theories.
Ann de Graaff, from the Max Planck Institute for Astronomy, shared, “The extreme properties of The Cliff made us rethink everything.” Further analysis revealed that it appears to be linked to a single supermassive black hole, enveloped by a fiery gas sphere rather than a crowd of tightly packed stars.
Interestingly, while supermassive black holes are usually at the heart of galaxies, scientists are still puzzled about how they grew so massive so fast. Typically, the processes that create these gigantic black holes take much longer than a billion years.
The “turbo-charged” growth of these black holes could explain how they became so massive in the early universe. Leja suggests that these black hole stars might represent the earliest stages of supermassive black hole formation we see today.
“No one really knew where these colossal black holes come from,” Leja added. “These black hole stars could be the foundational phase for what we observe in larger galaxies today.” The JWST will continue investigating these fascinating objects, hoping to unlock more secrets about their origins and characteristics.
The team’s findings, published in the journal Astronomy & Astrophysics, offer a new perspective on cosmic evolution. As our understanding of the universe expands, the clues these celestial bodies offer may lead to even more surprising discoveries.
