Early Universe's 'Little Red Dots' May Be Black Hole Stars (science.org) 16
After it began "peering into the distant universe" in 2022, NASA's James Webb Space Telescope "has discovered a rash of 'little red dots'," reports Science magazine. There's "hundreds of them, shining within the first billion years of the 13.8-billion-year-old universe, so small and red that they defied conventional explanation."
"Only in the past few months has a picture begun to emerge. The little red dots, astronomers say, may be an entirely new type of object: a colossal ball of bright, hot gas, larger than the Solar System, powered not by nuclear fusion, but by a black hole..." The objects, which some astronomers are calling "black hole stars," could be a missing link in the evolution of galaxies and help explain the rapid growth of supermassive black holes that lie at their hearts. "The big breakthrough of the past 6 months is actually the realization that we can throw out all these other models we've been playing with before," says astronomer Anna de Graaff of the Max Planck Institute for Astronomy... JWST couldn't resolve the dots into a recognizable shape, which meant they must have been tiny — less than 2% of the diameter of the Milky Way. "It was a mystery ... as to why they were so spatially compact," says Caitlin Casey of the University of Texas at Austin. An impossibly dense packing of stars would be needed to explain their brightness. "I was excited," Casey says...
For Mitch Begelman, a theoretical astrophysicist at the University of Colorado Boulder, the observations are a vindication. Earlier this month, he and a colleague posted a preprint on arXiv reviving a scenario for the formation of hypothetical "quasi-stars" that he and others had proposed 20 years ago. The first generation of stars, they calculated, could have grown to colossal size in the early universe, which was made up almost entirely of hydrogen, the raw material of stars. When a giant star ran out of fuel, they said, its core would have collapsed into a black hole, but the outer envelope of hydrogen was so dense it survived the blast, enclosing the newborn black hole. As the black hole chewed at its shroud of gas, the entire system glowed as a quasi-star larger than the Solar System. "That's what the quasi-star envelope is doing, it's force-feeding the black hole by pushing matter into it," Begelman says.
Given how common little red dots appear to be in the early universe, theorists are beginning to wonder whether this giant-ball-of-gas phase is an essential part of black hole growth and the evolution of galaxies. "We're probably looking at kind of a new phase of black hole growth that we didn't know about before," de Graaff says.
"If the red dots do turn out to be black hole stars, it will be precisely the sort of breakthrough expected from JWST — and the kind of discovery astronomers live for."
Thanks to Slashdot reader sciencehabit for sharing the news.
"Only in the past few months has a picture begun to emerge. The little red dots, astronomers say, may be an entirely new type of object: a colossal ball of bright, hot gas, larger than the Solar System, powered not by nuclear fusion, but by a black hole..." The objects, which some astronomers are calling "black hole stars," could be a missing link in the evolution of galaxies and help explain the rapid growth of supermassive black holes that lie at their hearts. "The big breakthrough of the past 6 months is actually the realization that we can throw out all these other models we've been playing with before," says astronomer Anna de Graaff of the Max Planck Institute for Astronomy... JWST couldn't resolve the dots into a recognizable shape, which meant they must have been tiny — less than 2% of the diameter of the Milky Way. "It was a mystery ... as to why they were so spatially compact," says Caitlin Casey of the University of Texas at Austin. An impossibly dense packing of stars would be needed to explain their brightness. "I was excited," Casey says...
For Mitch Begelman, a theoretical astrophysicist at the University of Colorado Boulder, the observations are a vindication. Earlier this month, he and a colleague posted a preprint on arXiv reviving a scenario for the formation of hypothetical "quasi-stars" that he and others had proposed 20 years ago. The first generation of stars, they calculated, could have grown to colossal size in the early universe, which was made up almost entirely of hydrogen, the raw material of stars. When a giant star ran out of fuel, they said, its core would have collapsed into a black hole, but the outer envelope of hydrogen was so dense it survived the blast, enclosing the newborn black hole. As the black hole chewed at its shroud of gas, the entire system glowed as a quasi-star larger than the Solar System. "That's what the quasi-star envelope is doing, it's force-feeding the black hole by pushing matter into it," Begelman says.
Given how common little red dots appear to be in the early universe, theorists are beginning to wonder whether this giant-ball-of-gas phase is an essential part of black hole growth and the evolution of galaxies. "We're probably looking at kind of a new phase of black hole growth that we didn't know about before," de Graaff says.
"If the red dots do turn out to be black hole stars, it will be precisely the sort of breakthrough expected from JWST — and the kind of discovery astronomers live for."
Thanks to Slashdot reader sciencehabit for sharing the news.
Would these be "black hole suns" (Score:4, Interesting)
And if so, should Soundgarden get some credit?
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Hahaha, that's the first place my mind went as well!
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Nope, that honor goes to CMOS image sensors from the 90s. See also: https://qph.cf2.quoracdn.net/m... [quoracdn.net]
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That post has to be a troll.
Re: Well... (Score:2)
Do you have physical proof of dark matter, or are stars in some galaxies orbiting as if gravity wasn't a constraint?
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Which papers discussing the various theories of dark matter posit that stars orbit somewhere "as if gravity wasn't a constraint".
Just the Arxiv links would be more than sufficient.
Re: Well... (Score:2)
Heard of Electric Universe theory? Is gravity a constraint at quantum scales, and might we be seeing something similar at super macro scales?
It's a black hole, I swear! (Score:2)
LRDs become galaxies (Score:3)
Re:LRDs become galaxies (Score:5, Informative)
This reminds me of the development of black hole theory that some scoffed at, or regarded as being irrelevant at least, until we started discovering black holes starting in 1971. The derivation of the Tolman–Oppenheimer–Volkoff limit in 1939 is probably the first physical analysis that demonstrated that black holes should exist.
That there should be a phase in the early Universe where immense stars of nearly pure hydrogen would form was predicted theoretically 20 years ago, predictions that got little attention as there was no observational data to support it. Until now. Yes, there are theorist who do know what they are doing and making correct predictions from physics.
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I remember reading the paper when it came out.
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JWST is showing us how the observed universe built itself.
But how do we make it show us the unobserved universe? ;)
God is an anti-vaxer (Score:1)
RFK was right! Measles good!