Webb Telescope Reveals Potential New Class of Celestial Object
Tiny red objects spotted by NASA’s James Webb Space Telescope (JWST) are offering scientists new insights into the origins of galaxies in the universe — and may represent an entirely new class of celestial object: a black hole swallowing massive amounts of matter and spitting out light.
using the first datasets released by the telescope in 2022, an international team of scientists including Penn State researchers discovered mysterious “little red dots.” The researchers initially suggested the objects may be galaxies that were as mature as our current Milky Way, roughly 13.6 billion years old, just 500 to 700 million years after the Big Bang.
Informally dubbed “universe breakers” by the team, the objects were originally thought to be galaxies far older than anyone expected in the infant universe – challenging what scientists previously understood about galaxy formation.
Now, in a paper published on Sept. 12 in the journal Astronomy & Astrophysics, the international team of astronomers and physicists, including those at Penn State, suggest that the dots may not be galaxies but an entirely new type of object: a black hole star.
Their analysis indicates that these tiny pinpoints of light may be giant spheres of hot gas,so dense they resemble the atmospheres of typical nuclear fusion-powered stars. However, instead of fusion, they are powered by supermassive black holes at their centre, rapidly pulling in matter, converting it into energy, and emitting light.
“Basically, we looked at enough red dots until we saw one that had so much atmosphere that it couldn’t be explained as typical stars we’d expect from a galaxy,” said Joel Leja, the Dr. Keiko Miwa Ross Mid-Career Associate Professor of Astrophysics at Penn State and co-author on the paper.”It’s an elegant answer really, because we thought it was a tiny galaxy full of many separate cold stars, but it’s actually, effectively, one gigantic, very cold star.”
Cold stars emit little light due to their low temperatures compared to normal stars, Leja explained. Most stars in the universe are low-mass, colder stars, but they are typically harder to see as they are washed out by rarer, more luminous massive stars. Astronomers identify cold stars by their glow, which is primarily in the red optical or near-infrared spectrum, wavelengths of light that are no longer visible. While the gas around supermassive black holes is typically very hot, millions of degrees Celsius…
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