Jupiter-Size Exoplanet Caught In the Act of Being Born (science.org) 16
sciencehabit shares a report from Science.org: Astronomers say they have witnessed a planet being born from a disk of gas and dust swirling around a young star. Such claims have been made before, but the team comes to an even more controversial conclusion: that this planet is forming from gas that is collapsing under its own gravity, a mechanism known as gravitational or disk instability. That stands in contrast to a more widely accepted theory of planet formation, in which dust and rocks stick together, slowly building up a planetary core with enough gravity to pull in gas from the disk. If true, the planetary system would be the strongest evidence to date for disk instability. "This system stands alone right now," says team leader Thayne Currie of the Subaru Telescope in Hawaii.
That conclusion is already dividing theorists. "This system certainly looks like it's [undergoing] disk instability," says Alan Boss of the Carnegie Institution for Science, a longtime advocate of the theory. But Anders Johansen, a theorist at the University of Copenhagen who helped develop the rival theory of core accretion, is not convinced. "This could be either mechanism," he says. Although more than 5000 exoplanets have been discovered, only a few tens have been imaged directly, and none in the act of being born. Currie and colleagues were intrigued by the nearby star AB Aurigae because it was young -- somewhere between 1 million and 4 million years old -- and because its disk contains kinked, spiral features that could indicate protoplanets. But showing that some of the light from its disk was from a glowing-hot new planet rather than reflected starlight was no easy task. "We sat on this result for 5 years," Currie says. "I did not believe it was a planet until fairly recently." The team published their findings in the journal Nature Astronomy.
That conclusion is already dividing theorists. "This system certainly looks like it's [undergoing] disk instability," says Alan Boss of the Carnegie Institution for Science, a longtime advocate of the theory. But Anders Johansen, a theorist at the University of Copenhagen who helped develop the rival theory of core accretion, is not convinced. "This could be either mechanism," he says. Although more than 5000 exoplanets have been discovered, only a few tens have been imaged directly, and none in the act of being born. Currie and colleagues were intrigued by the nearby star AB Aurigae because it was young -- somewhere between 1 million and 4 million years old -- and because its disk contains kinked, spiral features that could indicate protoplanets. But showing that some of the light from its disk was from a glowing-hot new planet rather than reflected starlight was no easy task. "We sat on this result for 5 years," Currie says. "I did not believe it was a planet until fairly recently." The team published their findings in the journal Nature Astronomy.
gravitational disk instability (Score:1)
Found it (Score:3, Funny)
Yo mama's so fat, that NASA had to launch a telescope into space so they could photograph the cosmos without her ass being in the frame.
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Yo mama, that planet is so big, when born it ripped the fabric of space-time to Uranus.
Re: gravitational disk instability (Score:2)
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Please, it's "birthing entity" not "mama" or "mother." Be considerate
Are you assuming that a birthing ( ) has to be an entity? No wonder we have a patriarchy.
I identify as nothing. Never refer to me.
It may be 9x the mass of Jupiter (Score:4, Funny)
But it hasn't cleared its orbit, so it's still a dwarf planet, officially.
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LoL.
We demand Pluto back - it might still be growing!
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It's not yet a planet at all, so your classification is already wrong in calling it a 'planet' :D
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And if you want to get super pedantic, it never will be. It could become an exoplanet, but not a planet.
Not being born (Score:2)
Obligatory degenerate meme (Score:1)
Will this planet become a brown dwarf (Score:1)
At this distance it is a bit far out to be what I'd have thought to be a planet but I'm no god that decides where planets can form.
With only 9 Jupiter masses the planet is short of the recognised 13 to become a brown dwarf but maybe there's enough matter left in orbit for the planet to grow some more and put on some weight to become one and for the system to eventually become a binary star system?
Which is to say arguing about how this planet is forming may be missing the obvious answer: it isn't formin
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TFS (written by Science staff journalists, not the scientists, or even Nature staffers) rather makes it sound as if the two models for planet formation are mutually exclusive, but a third option is that both processes can happen simultaneously, but in different regions of the circumstellar disc. In the inner parts of the disc, the heat of the
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The discussion about the putative Brown-Batygin 2016 "Planet 9" made various quite reasonable assumptions about the energy accumulated in forming the planet (a fairly simple function of the mass, and a not-so-simple questions about internal heat transport in the planet. If it has deep-reaching convection structures (because convection is generally more efficient at heat transport than conduction), so that most of the planet is invo
Pervs! (Score:1)
...mind your own business.