Stars May Form 10 Times Faster Than Thought (science.org) 17
An anonymous reader quotes a report from Science.org: Astronomers have long thought it takes millions of years for the seeds of stars like the Sun to come together. Clouds of mostly hydrogen gas coalesce under gravity into prestellar cores dense enough to collapse and spark nuclear fusion, while magnetic forces hold matter in place and slow down the process. But observations using the world's largest radio telescope are casting doubt on this long gestational period. Researchers have zoomed in on a prestellar core in a giant gas cloud -- a nursery for hundreds of baby stars -- and found the tiny embryo may be forming 10 times faster than thought, thanks to weak magnetic fields. "If this is proven to be the case in other gas clouds, it will be revolutionary for the star formation community," says Paola Caselli from the Max Planck Institute for Extraterrestrial Physics, who was not involved with the research.
Studying star birth and the tug of war between gravity and magnetic forces has been a challenge because the magnetic fields can be 100,000 times weaker than Earth's. The only direct way to detect them comes from a phenomenon called the Zeeman effect, in which the magnetic fields cause so-called spectral lines to split in a way that depends on the strength of the field. These spectral lines are bright or dark patterns where atoms or molecules emit or absorb specific wavelengths of light. For gas clouds, the Zeeman splitting occurs in radio wavelengths, so radio telescopes are needed. And the dishes must be big in order to zoom in on a small region of space and reveal such a subtle effect. Previously, researchers had used Puerto Rico's Arecibo radio telescope -- which collapsed in 2020 -- to study Lynds 1544, a relatively isolated stellar embryo within the Taurus Molecular Cloud, just 450 light-years away from Earth. They measured the magnetic fields in the wispy layers of gas far out from the core, where magnetic forces dominated over gravity. They also analyzed the stronger fields inside the core, where gravity nevertheless dominated because the core is 10,000 times denser than the outer layer, says Richard Crutcher, a radio astronomer at the University of Illinois, Urbana-Champaign. What was missing was an examination of the intermediate region between the core and the outer layer. That has now come into focus with a new tracer of the Zeeman effect -- a particular hydrogen absorption line -- detected by the Five-hundred-meter Aperture Spherical radio Telescope (FAST), a giant dish built inside a natural basin in southwestern China.
In a study published today in Nature, researchers report a magnetic field strength of 4 microgauss -- no stronger than in the outer layer. "If the standard theory worked, the magnetic field needs to be much stronger to resist a 100-fold increase in cloud density. That didn't happen," says Di Li, the chief scientist of FAST who led the study. "The paper basically says that gravity wins in the cloud: That's where stars start to form, not in the dense core," Caselli adds. "That's a very big statement." The finding implies that a gas cloud could evolve into a stellar embryo 10 times quicker than previously thought, says lead author Tao-Chung Ching of the Chinese Academy of Sciences's National Astronomical Observatories. Li says he wants to study other molecular clouds to see whether the lessons from Lynds 1544 apply more generally.
Studying star birth and the tug of war between gravity and magnetic forces has been a challenge because the magnetic fields can be 100,000 times weaker than Earth's. The only direct way to detect them comes from a phenomenon called the Zeeman effect, in which the magnetic fields cause so-called spectral lines to split in a way that depends on the strength of the field. These spectral lines are bright or dark patterns where atoms or molecules emit or absorb specific wavelengths of light. For gas clouds, the Zeeman splitting occurs in radio wavelengths, so radio telescopes are needed. And the dishes must be big in order to zoom in on a small region of space and reveal such a subtle effect. Previously, researchers had used Puerto Rico's Arecibo radio telescope -- which collapsed in 2020 -- to study Lynds 1544, a relatively isolated stellar embryo within the Taurus Molecular Cloud, just 450 light-years away from Earth. They measured the magnetic fields in the wispy layers of gas far out from the core, where magnetic forces dominated over gravity. They also analyzed the stronger fields inside the core, where gravity nevertheless dominated because the core is 10,000 times denser than the outer layer, says Richard Crutcher, a radio astronomer at the University of Illinois, Urbana-Champaign. What was missing was an examination of the intermediate region between the core and the outer layer. That has now come into focus with a new tracer of the Zeeman effect -- a particular hydrogen absorption line -- detected by the Five-hundred-meter Aperture Spherical radio Telescope (FAST), a giant dish built inside a natural basin in southwestern China.
In a study published today in Nature, researchers report a magnetic field strength of 4 microgauss -- no stronger than in the outer layer. "If the standard theory worked, the magnetic field needs to be much stronger to resist a 100-fold increase in cloud density. That didn't happen," says Di Li, the chief scientist of FAST who led the study. "The paper basically says that gravity wins in the cloud: That's where stars start to form, not in the dense core," Caselli adds. "That's a very big statement." The finding implies that a gas cloud could evolve into a stellar embryo 10 times quicker than previously thought, says lead author Tao-Chung Ching of the Chinese Academy of Sciences's National Astronomical Observatories. Li says he wants to study other molecular clouds to see whether the lessons from Lynds 1544 apply more generally.
We need to rebuild the Arecibo radio telescope (Score:3)
Re: (Score:2)
I don't really need telescopes, I just watched "2001: A Space Odyssey" back then so I already have known for a long time stars form really quickly. /s
Re:We need to rebuild the Arecibo radio telescope (Score:5, Funny)
That is because everything seems fast in comparison with that movie
Re: (Score:2)
BRAVO! I wish I had mod points. I legit laughed out loud at this one.
Don't get me wrong. When I'm in the right mood I love that movie. But there's no denying it drags HARD in places.
Re: (Score:2)
Actually I liked it too. And the pace of the movie was by design of course which makes it easier to adapt to it.
Re: (Score:2)
There is a lot of good research we could being doing. It's a pity that this classic telescope collapsed. Time to rebuild it so it can add to this area of research.
The chauvinists in Congress will approve funding for a new Arecibo along about the third paper from chief scientists Di Li and lead researcher Tao-Chung Ching. Names like that get a certain kind of congresscritter up on their hind legs real quick. "We can not allow a telescope gap!" The other kind of congresscritter will go along with it because "Science!"
Honestly I'm surprised it hasn't happened already. It's bipartisan, it's not that much money as these things go, and it plays really well with the pub
Confinement (Score:2)
If I get it right the magnetic field slows down the contraction of the cloud because the charged particles circle around the field lines similar to how magnetic confinement works to contain the hot plasma in a tokamak fusion reactor. But maybe corona is a more relevant example, and with that I mean Northern Lights.
I don't get it. (Score:1)
I don't get it, I can form a though pretty much instantly. How can stars form 10 times faster?
Re: (Score:2)
Re: (Score:2)
We humans can form thoughts pretty quickly. But really tiny lizards have some of the quickest thoughts because it takes less time for the neurons to pass messages across a physically smaller brain. Star thoughts take a long time because their star brains are so large.
That is amazing speed! (Score:2)
Thus my Indic language brain interpreted the headline as "you think about stars being formed, before your thought is complete, the stars have been formed!"
I don't know about that. I can think pretty fast. (Score:3)
My inner editor got very annoyed by the title here. One word could have fixed it.
Stars May Form 10 Times Faster Than Thought
That made me recoil.
Stars May Form 10 Times Faster Than Previously Thought
Sorry. I've been editing novels for the past few weeks and I think I can't turn it off now.
My inner editor concurs (Score:2)
The problem is that the person who wrote this title doesn't realize how much is revealed about their communication skills in 8 simple words.
Re:My inner editor concurs (Score:4, Insightful)
Since I've taken up editing as a hobby, the editing on Slashdot has really started bringing me down. You'd think this place gets enough traffic to at least hire a hobby level editor. And I'm sure I miss some stuff as I'm just getting started on this particular path. Still, about nine out of ten stories hit my cringe-o-meter hard.
Faster than thought? (Score:2)
I don't know about that. Thoughts form pretty fast.
Sounds similar to plasma cosmology (Score:1)