This May Be the First Planet Found Orbiting 3 Stars at Once (nytimes.com) 51
GW Ori is a star system 1,300 light years from Earth in the constellation of Orion. It is surrounded by a huge disk of dust and gas, a common feature of young star systems that are forming planets. But fascinatingly, it is a system with not one star, but three. From a report: As if that were not intriguing enough, GW Ori's disk is split in two, almost like Saturn's rings if they had a massive gap in between. And to make it even more bizarre, the outer ring is tilted at about 38 degrees. Scientists have been trying to explain what is going on there. Some hypothesized that the gap in the disk could be the result of one or more planets forming in the system. If so, this would be the first known planet that orbits three stars at once, also known as a circumtriple planet.
Now the GW Ori system has been modeled in greater detail, and researchers say a planet -- a gassy world as massive as Jupiter -- is the best explanation for the gap in the dust cloud. Although the planet itself cannot be seen, astronomers may be witnessing it carve out its orbit in its first million years of its existence. A paper on the finding was published in September in the Monthly Notices of the Royal Astronomical Society. The scientists say it disproves an alternative explanation -- that the gravitational torque of the stars cleared the space in the disk. Their paper suggests there is not enough turbulence in the disk, known as its viscosity, for this explanation to suffice The finding also highlights how much more there is to learn about the unexpected ways in which planets can form.
Now the GW Ori system has been modeled in greater detail, and researchers say a planet -- a gassy world as massive as Jupiter -- is the best explanation for the gap in the dust cloud. Although the planet itself cannot be seen, astronomers may be witnessing it carve out its orbit in its first million years of its existence. A paper on the finding was published in September in the Monthly Notices of the Royal Astronomical Society. The scientists say it disproves an alternative explanation -- that the gravitational torque of the stars cleared the space in the disk. Their paper suggests there is not enough turbulence in the disk, known as its viscosity, for this explanation to suffice The finding also highlights how much more there is to learn about the unexpected ways in which planets can form.
Paywall (Score:2, Insightful)
Cool story. Shame Slashdot insists not posting stories not everyone can read without jumping through hoops.
The rest of the circumtriple story (Score:4, Informative)
Anyone who has watched George Lucas’ original “Star Wars” is familiar with planets that can have two stars rising and falling in its skies. Luke Skywalker’s dusty home of Tatooine was in such a binary star system. But a planet orbiting three stars would be more unusual.
If a familiar life form could dwell on a gas giant like the one that would be orbiting GW Ori, it would not actually be able to see the three stars in its skies. Rather, they would see only a pair as the two innermost stars orbit so close as to appear like a single point of light. Yet as the planet rotated, its stars would rise and fall in fascinating sunrises and sunsets unlike any other known world.
“‘Star Wars’ missed a trick,” said Rebecca Nealon from the University of Warwick in England, a co-author on the paper.
Scientists have been on the lookout for a planet orbiting three stars, and found potential evidence in another system, GG Tau A, located about 450 light years from Earth. But the researchers say the gap in GW Ori’s gas and dust ring makes it a more convincing example.
“It may be the first evidence of a circumtriple planet carving a gap in real time,” said Jeremy Smallwood from the University of Nevada, Las Vegas, lead author of the new paper.
William Welsh, an astronomer at San Diego State University, said the researchers “make a good case. If this turns out to be a planet, it would be fascinating.”
Alison Young from the University of Leicester in England who has argued that GW Ori’s stars caused the gap in the system’s disk, rather than a planet, notes that observations from the ALMA telescope and Very Large Telescope in Chile in the coming months could end the debate.
“We’ll be able to look for direct evidence of a planet in the disk,” Dr. Young said.
If the planet hypothesis is confirmed, the system would reinforce the idea that planet formation is common. Several worlds, known as circumbinary planets, are already known to orbit two stars at once. But circumtriple planets have been harder to come by — despite estimates that at least a tenth of all stars cluster in systems of three or more. Yet their possible existence suggests that planets spring up in all sorts of places, even here in this most bizarre of systems.
“Three stars is not enough to kill planet formation,” Dr. Nealon said.
That suggests that exoplanets are likely to arise in more and more unusual locations. “What we’ve learned is any time planets can form, they do,” said Sean Raymond, an astronomer from the University of Bordeaux in France who was not involved in the paper.
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And once every 22 years, all three star are eclipsed, throwing the planet into darkness. And then only Riddick can save you from the flesh-eating monsters.
Re:The rest of the circumtriple story (Score:4, Informative)
I suppose that some will thank you for that, but copying it is a breach of copyright. I read the text without problem - the noscript plugin stopped the obscuring javascript from running.
Re:The rest of the circumtriple story (Score:5, Insightful)
I suppose that some will thank you for that, but copying it is a breach of copyright
Nobody cares. Current copyright laws are awful and everyone ought to break them as often as possible.
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I suppose that some will thank you for that, but copying it is a breach of copyright. I read the text without problem - the noscript plugin stopped the obscuring javascript from running.
I beg your pardon, sir. I have a subscription I am legally allowed to share with a hand full of hoomans... is it your contention that I would exceed those limits posting on the Slashdot?
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Thanks, but I shouldn't have to thank you. Slashdot was once a place promoting freedom and open source. They should just have posted an archive link. We need to call editors out for their bullshit.
Not that weird (Score:2)
Double star systems are quite common. Triples are a little rare but not unheard of. It was only a matter of time before we found planets in one of those systems, hampered a bit by some of the methods of planet detection not working well in complex systems (e.g. looking for wobbles).
Only saved by it being a good thing to get people excited about astronomy.
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I suspect were not going to find life on one of these planets though. The orbits going to be pretty unstable. In fact its a surprise planets are possible at all because of the instability of its orbit. This thing would be under some very harsh extremes.
Its been a while since I read it, but I *think* it was a three star system that the Trisolaris's come from in "Three Body Problem", and the Trisolaris's have an adaption where during the dry seasons they completely dehydrate and flatten, reviving once that se
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I think any real instability will be over very long periods of time, and that seasons would be entirely predictable (just not necessarily as easy as a loop).
Sci-Fi would tend to play up oddity. Maybe that species is just almost innumerate.
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Please keep in mind that this doesn't say we've discovered a planet. It merely suggests that a planet might have been involved at some point in the past. That planet may never have existed, nor does that planet need to still exist. It may have been destroyed long ago.
So we still have absolutely zero discovery of a planet orbiting three stars. We have a maybe-planet, and we have three starts, but we haven't found them to be concurrent at all.
We found large metropolitan cities. We found fossils of dinos
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Modelling the formation of planets is complex, but most models of forming the Solar system have Jupiter taking about 5 million years to form, the terrestrial planets 25 to 100 million years to form. From a planetary point of view, this star doesn't have a meaningful past.
Is the term "Orbit" apply here? (Score:2)
According to Nasa (https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-orbit-58.html):
An orbit is a regular, repeating path that one object in space takes around another one.
What do you call it when an object is space has a stable (I'm presuming this) trajectory in a system with two or three stars? I would think that the path would be very irregular, which violates the definition of "orbit".
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That probably depends entirely on proximity and relative gravity fields. I would have to think it's possible one star is the host and the other two orbit the host star along with the planet(s). I realize Jupiter isn't quite there, but with enough added mass we could be in exactly that situation in our own solar system. I would think that scenario is at least as likely as a scenario where you end up with two or three equal(ish) massive stars all circling each other. I'm not even sure how that could stabi
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The planet would be at a fair distance, so it would simply orbit around the center of mass of the triple star system. The stars are all within around 10AU of each other with most of the mass concentrated in the close (1.25AU) binary AB, while the planet's orbit would be somewhere in the neighborhood of 100AU from the center (can't read the article so I'm just basing this on where the gap is). GW Ori C would influence the planet's orbit the same way e.g. Jupiter affects Neptune's, but the distances are even
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So the planet would not be habitable then
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No, and not just because of the distance. This star system is so young (around a million years or even less) that the planet may not even have finished coalescing. Habitability is also out of the question because it's likely a massive gas giant if it's able to carve such a large gap in the dust.
The two primary stars are quite a bit more massive (and therefore more luminous) than the Sun so the habitable zone would be rather wide, but probably not out to the 100AU neighborhood. Tossing some numbers around, t
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Hmmm, That's an interesting idea. Somebody played with a similar idea back ... well I remember reading it in the mid-80s, so before then. I'm trying to remember the author now ... Aldiss, the Heliconia trilogy [wikipedia.org], and I must have read it when it was relatively new.
Unfortunately, if the development of life on Ea
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I think you are putting waaaay too much authority in NASA's page for students in grades 5 to 8. To call that page the one and only definition of an orbit is probably overstating things. It's not an encyclopedia, it's not a professional society or standards committee. It's an educational page meant for budding
Re: Three body problem (Score:2)
The âoebroken ringâ is a still unfolded Sophon, when we see the spikey trails of dust in the systems heliosphere, weâ(TM)ll know they are on the move towards earth
canâ(TM)t wait for the Netflix adaptation. Itâ(TM)ll be done by the same clowns who shat the bed with game of thrones, but since all the books are done, they wonâ(TM)t have to resort to their hack writing skills and might actually deliver an epic series start to finish this time
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9780765382030
Do not answer (Score:5, Funny)
Do not answer. Do not answer.
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Nice to know that another one here read Cixin Liu
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At least it is not only 4 light years away....
I wonder if they'll write a book about it (Score:2)
A thinly disguised Commie propaganda piece ?
Three Body Problem was okay, but still chock full of Dear Leader Xi panderings.
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The science fiction in it was quite good. The rest of it was utter garbage. I find it hard to believe that Chinese people are as written in the books.
He writes good science fiction but horrible dialogue and characters.
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I got the vibe it was partially a translation problem and partially a culture shock problem. But what the hell do I know? I only took half a semester of mandarin, so Chinese culture isn't exactly my strong suit.
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Really? So you read that book, including the first chapter, a full throated denounciation of Cultural Revolution china , one that caused the publisher and author to worried they'd get punished by the state, and conclude its 'commie propaganda'?!
Or are you just reacting to the word "China"?
Tough neighborhood (Score:3)
I wonder if the sentient beings evolved on that planet end up devising a solution to the 3-body problem.
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Some a lot closer (Score:3)
Pretty sure Alpha Centuri is a triple star system with planets also, and a fair bit closer
Link to the source (Score:4, Informative)
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The author list is different too.
As far as I can tell, the paper is https://arxiv.org/pdf/2004.012... [arxiv.org] (63 pages, horribly slow to load, April last year) with a prettier 9 page presentation by the team leader from December at https://arxiv.org/abs/2012.065... [arxiv.org]
Three Body Problem (Score:2)
Imagine trying to predict where the sun is going to rise.
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ooops, forgot the link to what the orbits look like [wikipedia.org]
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That isn't the orbits of this star system, that's a theoretical model of a generalised 3-body system.
Indeed, I should have said it was an example - thanks for pointing that out.
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No Dark Crystal reference? (Score:2)
"When single shines the triple sun, what is sundered and undone, shall be whole, the two made one."
Smoke Ring (Score:3)
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Ori? (Score:2)