Tiny, glowing red dots seen by NASA’s James Webb Space Telescope (JWST) could be one of the biggest surprises in modern astronomy.
At first, scientists thought these objects were galaxies that had already grown large and mature just a few hundred million years after the Big Bang.
That idea alone shocked researchers, since it didn’t match our understanding of how galaxies form.
But now, an international team of scientists, including researchers from Penn State University, thinks these dots might be something else entirely: a new kind of cosmic object called a “black hole star.”
A puzzle in the early universe
When JWST started sending back its first images in 2022, astronomers noticed faint but bright red pinpoints scattered across the early universe.
Because red light often comes from older stars, scientists believed these were mature galaxies that had formed extremely early—so early that it seemed impossible.
The team jokingly called them “universe breakers” because, if true, they would break existing theories about how galaxies grow.
But as they looked more closely, the data didn’t add up. These supposed galaxies were far too bright and massive for their age.
If they really contained so many stars packed into such small spaces, the night sky within them would have been dazzlingly bright—something nature isn’t likely to allow.
What are “black hole stars”?
The new explanation is more exotic. The researchers suggest that these red dots are not galaxies at all, but giant spheres of gas wrapped around young supermassive black holes.
Here’s how it might work: the black hole pulls in huge amounts of nearby gas. Instead of forming normal stars, the gas builds up into a single enormous atmosphere.
This atmosphere glows like a star, but it isn’t powered by nuclear fusion, as with our sun. Instead, the glow comes from the black hole at its center, converting falling matter into energy.
This could make the object appear like a gigantic, cold, reddish star—something completely different from what we’ve seen before.
To test this idea, the team used about 60 hours of JWST time between January and December 2024 to collect spectra—detailed breakdowns of the light from these objects. Spectra help astronomers figure out what elements are present and how much mass is involved.
In July 2024, they spotted the most extreme case yet, nicknamed “The Cliff.” Its spectrum revealed an enormous amount of mass and energy that couldn’t be explained by normal stars. Instead, it looked exactly like a black hole swallowing matter at incredible speed and wrapping itself in a thick, glowing shell of hydrogen gas.
This finding suggests that black hole stars might have been common in the early universe.
Every galaxy we know today has a supermassive black hole at its center, but astronomers have never been sure where those black holes originally came from. Black hole stars might be the missing link—the very first stage in the birth of supermassive black holes.
If so, these objects could help explain how such massive black holes already existed so early in cosmic history. They also show that the universe may be stranger than we imagined.
As Joel Leja, a Penn State astrophysicist involved in the work, put it: “It’s okay to be wrong. The universe is much weirder than we can imagine and all we can do is follow its clues.”
For now, scientists will keep watching these mysterious red dots. Whether they turn out to be black hole stars or something else entirely, they are already rewriting what we thought we knew about the beginnings of the universe.
Source: Penn State.
