A Star With Six Planets That Orbit Perfectly in Sync (nytimes.com) 30
Astronomers have discovered six planets orbiting a bright star in perfect resonance. The star system, 100 light-years from Earth, was described on Wednesday in a paper published in the journal Nature. From a report: The discovery of the system could give astronomers a unique opportunity to trace the evolution of these worlds to when they first formed, and potentially offer insights into how our solar system got to be the way it is today. "It's like looking at a fossil," said Rafael Luque, an astronomer at the University of Chicago who led the study. "The orbits of the planets today are the same as they were a billion years ago."
Researchers think that when planets first form, their orbits around a star are in sync. That is, the time it takes for one planet to waltz around its host star might be the same amount of time it takes for a second planet to circle exactly twice, or exactly three times. Systems that line up like this are known as orbital resonances. But, despite the theory, finding resonances in the Milky Way is rare. Only 1 percent of planetary systems still preserve this symmetry.
Most of the time, planetary orbits get knocked out of sync by an event that upsets the gravitational balance of the system. That could be a close encounter with another star, the formation of a massive planet like Jupiter, or a giant impact from space on one planet that causes a ripple effect in other orbits. When this happens, Dr. Luque said, planetary orbits become too chaotic to mathematically describe, and knowledge of their evolution is indecipherable. Astronomers are lucky to find even one pair of exoplanets in resonance. But in the newly discovered star system, there are a whopping five pairs, because all six planets have orbits that are in sync with one another. Dr. Luque described it as "the 1 percent of the 1 percent."
Researchers think that when planets first form, their orbits around a star are in sync. That is, the time it takes for one planet to waltz around its host star might be the same amount of time it takes for a second planet to circle exactly twice, or exactly three times. Systems that line up like this are known as orbital resonances. But, despite the theory, finding resonances in the Milky Way is rare. Only 1 percent of planetary systems still preserve this symmetry.
Most of the time, planetary orbits get knocked out of sync by an event that upsets the gravitational balance of the system. That could be a close encounter with another star, the formation of a massive planet like Jupiter, or a giant impact from space on one planet that causes a ripple effect in other orbits. When this happens, Dr. Luque said, planetary orbits become too chaotic to mathematically describe, and knowledge of their evolution is indecipherable. Astronomers are lucky to find even one pair of exoplanets in resonance. But in the newly discovered star system, there are a whopping five pairs, because all six planets have orbits that are in sync with one another. Dr. Luque described it as "the 1 percent of the 1 percent."
15 pairs? (Score:1)
I think she meant 15 pairs
Re: 15 pairs? (Score:5, Interesting)
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Doesn't just have to be the nearest planets, gravity drops off over distance but it's never zero. So Saturn could affect Mars slightly, especially over millions of years. Of course, in our solar system the distance between the planets as you go outwards is immense. The non-scale models doesn't make this clear: light from the sun reaches earth in a little over 8 minutes, and reaches Jupiter in 43 minutes, and reaches Neptune after 4 hours.
For this particular system, the 6 planets are all closer to the sta
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>So Saturn could affect Mars slightly, especially over millions of years
Yes, but I presume Jupiter and Earth have stronger effects that pull it back into place.
That's why resonances exist - it's mutual tugging of neighbouring bodies that gets them into those regular patterns.
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In orbital dynamics, there is no "place" to pull it back into. Everything is dynamic and nothing is long term stable.
Jupiter, being the biggest, is the dominant influence in the inner solar system, but because Neptune gets closer to the outer solar system than Jupiter does, Neptune is relatively important in the outer solar system. But really, you do have to include all of the 8 planets when calculating them motions of the "small bodies".
Alternate site ... (Score:5, Informative)
Time [time.com]
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Thank you Captain!
Screw you msmash for pointing to another vile paywalled site. Do you get a comission for that junk?
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Thank you Captain! Screw you msmash for pointing to another vile paywalled site. Do you get a comission for that junk?
Yes, they pay commission. The NY Times has a secret program to pay random Internet commenters large sums of money to post links. They were inspired by the ten million people paid by George Soros to post subtly stupid internet comments on politics. There's an entire multi-billion dollar industry of micro payments just to annoy micro penises like yourself.
Re: (Score:2)
I do not associate myself with this remark.
Re:Alternate site ... and TFP. (Score:2)
There should be a paper somewhere ... ah, here it is : A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067 [arxiv.org] by about 150 authors.
TFP : key points. (Score:2)
That's a northern (celestial) hemisphere constellation. But with a fairly high HD (Henry Draper catalogue) number, it's not likely to be amenable to your diddy amateur telescope. Some of the radial velocity work was done with 20cm telescopes at Paranal (Chile)
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This is why we need to look out there (Score:2)
Some folks think that we know everything about the laws of physics, and what might exist out in the universe. This is an example of an extremely cool phenomenon that I don't think anyone would have expected, or really even dreamed of before we saw it ourselves. We don't know the smallest percentage about what is out there. We need to keep looking, seeking, exploring.
Dark Matter and Energy (Score:2)
Some folks think that we know everything about the laws of physics, and what might exist out in the universe.
Nobody thinks that given that we know 25% of the universe is Dark Matter and 70% is Dark Energy - neither of which we know anything about. The entirety of science so far comes from studying what makes up just 5% of the universe. We literally know that we don't know everything out there.
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Assumptions are not Knowledge (Score:2)
Errr, we do know that "Dark Matter" gravitates in the same way as the 5% or so of the universe that is just "matter"
Actually, we are assuming that and using it to calculate the size of the missing mass. We do not _know_ it but in the absence of any evidence that DM gravitates differently, it is the simplest, and hence most reasonable, assumption...but no matter how reasonable it is, it is still an assumption.
Off balance? (Score:1)
This should walk that star across the universe like an off-balance washing machine.
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Without friction, the washing machine wouldn't walk across anything, it would be happy doing its dance in one spot.
Magrathea? (Score:2)
Maybe this didn't happen by accident?
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Are any of these planets habitable?
Interesting. (Score:2)
A lot of solar systems that have been observed have planets with highly eccentric orbits. Indeed, it's thought that in our solar system, Jupiter had such an orbit and destroyed the original inner planets, gaining its current orbit when Saturn formed. It's only then that new inner planets formed. And two of those collided to form the Earth and moon.
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Citation required. I've not heard anyone (except you, here) making that claim.
I think you're probably mis-remembering the "Grand Tack" model of the early (first ~20 million years) Solar system which hypothesises that Early Jupiter and Early Saturn ("Early" because they were still growing at the time) migrated inwards by several AU from their origin, until they entered a near-resonance (2:1 perio
The six-body problem (Score:2)
Soon in your bookstores and later on your streaming channel.
Puppeteer homeworld? (Score:2)
They don't say anything about the homestar being under acceleration, so maybe they haven't moved in yet.
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Not "perfect," just relatively perfect. (Score:2)
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Hmmm, I didn't notice a radial distance to the system anywhere in the paper, but I only skimmed it, not cover-to-cove
Not impressed... (Score:2)