Can a star orbit a planet
In: Planetary Science
Short answer is no.
Long answer is, the bigger mass causes the orbit.
And if the planet was more massive than the star, than it would become a star.
Even the smallest stars is about the 100x the mass of Saturn
If anything will cause an orbit. It’ll be heavier. And if a star is orbiting it, it’s either another star or a black hole.
A planet with enough mass to hold a star in its orbit would have turned into a star on own.
Not very likely. Probably not possible given our current understanding of the universe.
A lot of the discussion here is pitched toward naturally occurring systems and the vague line drawn between super-Jupiters and Brown dwarf stars.
There may be a more nuanced discussion that could be had by astrophysicists and materials scientists. Specifically:
– what would be the theoretical minimum mass for a star of any kind without the limits imposed by natural formation (hand-picked materials and starting configuration)
– what is the theoretical maximum planetary mass (again without natural formation limits)
With regards to the star, are we talking brown dwarf still? White dwarf? Is a white dwarf even a star if fusion is long since over and done? Black dwarf? Would a black dwarf be considered a star?
With regards to the planet would the most massive really be a super-Jupiter? Could a solid chunk of iron reach a greater mass since it can’t fuse (I think)? What is the best material/mix for the planet mass taking degeneracy pressure into account for the upper mass limit? Is iron a prime candidate, or would alternative materials permit it to get more massive?
Technically, yes.
You ever see the olympic sport where they spin around with a rope and a weight at the end?
The person would be the sun, and the planet would tend to be the planet. The person spinning does move slightly around, they aren’t perfectly center.
Same thing tends to happen with stars and planets, they all orbit each other but the one with the most mass tends to ‘swing’ the other planets more. Like with the sun, it’s pretty damn big and heavy, and if you watch an orbit simulation, the sun wiggles a little around an axis, it doesn’t stay perfectly centered
I’ll take “Star orbit a planet” to mean that the Lagrange point is closer to the star than the planet (meaning the planet is much, much more massive, and the star tends to go around the planet rather than the other way around)
Given how stars and star systems form, it’s *very* unlikely. Dust clouds swirl around what eventually becomes a star. The star is where most of the mass – over 99% – from the star system is concentrated. There just isn’t enough left in the local dust clouds for a planet that big.
But still, in the scheme of the universe, strange things can still happen. A burned out star can look a lot like a planet, and every once in a while two solar systems can go careening through each other, enough to mix things up, and a dead star bigger than the star at the middle of a tiny star system could pull that star into its orbit.
So it’s a maybe.
*Lighter* things orbit *heavier* things. If the *heavier* thing is a planet then the *lighter* thing can’t be a star. A star is a star because it got so massive that it turned itself into a nuclear fusion reactor. So, if the *lighter* object is a star then the *heavier* object must also be a star (or something even heavier, like a black hole).
Technically celestial objects orbit each other, but the heavier thing is usually *so much* heavier that it’s hard to notice the larger object moving. Pluto and its largest moon Charon co-orbit each other like the thing you throw in Ladderball.
Theoretically a star could orbit a planet, but the star would be very tiny and the planet would be very massive for it to happen. This is unlikely to exist.
Technically, jupiter does NOT orbit our sun, it is so massive that the sun and jupiter both orbit around a central point called a barycenter which is 0.07 solar radius above the surface of the sun.
The rest of the planets also have a barycenter with the sun but they are all inside the sun.
Stars and planets orbit a common point, called a barycenter. Planets don’t technically orbit the stars, they both swing around the barycenter. Think of two people holding hands and twirling around.
The only difference is that one person is King Kong, the other is a child. King Kong will *always* be in the middle, the child will never be able to swing King Kong around them.
So no, a planet will never orbit a star. A tiny red-dwarf and a large brown-dwarf might orbit a barycenter that’s outside the surface of either though.
Eli5: no.
Eli16: a star can orbit another star that has a planet orbiting it so… Technically not the planet but it’s going around it like an orbit.
In theory yes, but finding planets massive enough with dwarf stars small enough to make this happen would be exceedingly rare, almost impossibly rare if you want the barycenter inside the planet. Your best chances are for a brown dwarf to catch a red/white dwarf.
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