Astroboffins baffled after spotting solar system with great gas giant that shouldn't exist A gas giant orbiting a tiny red dwarf star thirty light years away has left astronomers baffled because it's not supposed to exist. That's according to a study published in Science on Thursday. Under the standard model of planet formation, the object known as GJ 3512 b should have never been born as it’s considered almost …
"Kepler's laws only apply around a common star."
I deleted a rather long caveat about this. (I've learnt my lesson.) Yes, you have to know the region a set of rules operate in. But, as you point out, it was fine. We were trying to determine the orbital "radius" of the planet and a quicker orbit around a lighter star means it must be closer in than the earth.
(And while I'm here, I meant aphelion---or apastron, if you're being a real pedant---not apogee.)
is very simple and very naive. It requires a uniformity in the accretion disk that I find hard to imagine in 2nd generation systems where the concentration of material that sets the thing going is likely to come from the collision of two or more shock wave from supernova and some interstellar junk as well.
Just looking at the remnants that adorn the heavens today you should be able to imagine places where large planets form in clumps of 'disk' long before other parts collapse to form stars as a(?) shock wave passed through. For every nice accretion disk there are a billion acned teenagers faces that will also form planetary systems.
Most stars seem to have companion stars (binary, etc.). It may be that these are two gas eddies that formed at the same time. The "gas planet" may simply be a very poor attempt at a companion star rather than being formed from the leftovers from the creation of the main star.
My thought too. As for migrating in, most gas giants we have found are hot Jupiters. It's thought that Jupiter started to migrate in but was hauled back by the formation of Saturn. That also explains the small size of Mars and the asteroid belt. The belt mass was prevented from accreting to Mars by Jupiter's movement and gravity.
But natural experiments like this and our own system are what drives the evolution of our models. Scientific models are like battle plans. In the ideal world they should fall apart quite often in contact with reality.
"Most stars seem to have companion stars (binary, etc.). It may be that these are two gas eddies that formed at the same time."
As far as I can tell, that's exactly what the paper suggests:
"We therefore considered a competing model of planet formation by gravitational instability of the gas disk at very young ages, when the disk is still massive relative to the star"
Basically, they say that models assuming the planet formed by having lots of little rocks collide long after the star has formed don't work, but assuming the planet and star formed around the same time directly from the gas cloud work quite well. Which doesn't sound particularly revolutionary at all; far from overturning the standard model of planet formation, it just says that in this particular case one of the ways bodies can form doesn't work but the other way we already knew of does.
Edit: I should note that the paper seems absolutely fine, they just say "Here's a fairly rare thing to see, we checked the two ways we think it could have happened and only the second one fits.". It's just a bit disappointing to see El Reg engaging in the shoddy tabloid "Einstein Proven Wrong!" style of science reporting. Astroboffins are not baffled, and no-one ever claimed this planet should not exist. The science is interesting enough on its own, it doesn't need this kind of overblown clickbait nonsense to try to sell it.
Seems the most likely explanation. One eddy in the collapsing gas and dust cloud just made it to stellar mass, the other didn't. Probably halted as the red dwarf reached ignition mass and density dispersing the rest of the cloud via radiation pressure.
Twin baby stars grow amongst a twisting network of gas and dust
https://www.sciencedaily.com/releases/2019/10/191004095938.htm
Image https://www.google.com/search?q=BHB2007&client=firefox-b-d&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjwjMO4ooflAhWGQUEAHR2lAgUQ_AUIESgB&biw=1150&bih=767#imgrc=hBLeVGPM6D7QtM:
Possibly captured from a different star during a very rare but not impossible close encounter; crowded or busy stellar clusters can I believe eject members; or the Gas Giant itself was ejected from a different system during a turbulent youth and captured by the minnow it currently orbits.
As you can see from my handle, I'm no Astro-boffin, this is pure speculation
We expect planetary captures to be quite rare. This is because the amount of potential + kinetic energy between two objects remains constant unless some third source intervenes. See for example, the two comets from "out there"--they leave & don't come back.
The problem is, this system is only 30 light years away, which means that you're dealing with the 1 in million chance happening 90% of the time problem.
Another commentard has claimed to have read the paper, which basically says that this gas giant is really a failed binary star. So no need for capture.
"Astroboffins baffled after spotting solar system with great gas giant that shouldn't exist"
^ Then that says that the existing models of solar system formation are incomplete/inaccurate/both. Instead of whining, drop all the prejudices about what is and is not possible when it comes to planet formation and come up with a better model. Simples, innit?
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