Polar solar orbit possible?

  • #1
990
342

Main Question or Discussion Point

I need a planet to be orbiting it's sun in a polar orbit. Is this a stable configuration?
 

Answers and Replies

  • #2
3,379
943
It's unlikely that this could easily arise since a star and it's associated planets all form out of the same collapsing dust\gas cloud.
So the larger bodies which form tend to all inherit similar angular momentum.
I don't think there is anything which absolutely rules out that a planet might end up in a polar orbit of it's parent star.
In stellar systems having more than two large stars gravitationaly bound, it sounds plausible.
Then again, that setup might lead to chaotic planet orbits, although a planet might be in a polar orbit of one star for a while.
 
  • #3
990
342
Okay, "natural" is out, what about a captured planet? Would a planet who wanders into a system have a chance of achieving a stable polar solar orbit? This would be the only planet in the system, with very low junk around the star before the wanderer arrived.
 
  • #4
Bandersnatch
Science Advisor
2,914
1,823
If it's the only planet, then how do you decide whether the orbit is polar or planar?

Rogue planet capture needs a third body to interact with, otherwise it'll just continue on a hyperbolic trajectory away from the system.
 
  • #5
990
342
If it's the only planet, then how do you decide whether the orbit is polar or planar?

Rogue planet capture needs a third body to interact with, otherwise it'll just continue on a hyperbolic trajectory away from the system.
Doesn't our sun rotate?
 
  • #6
990
342
Rogue planet capture needs a third body to interact with, otherwise it'll just continue on a hyperbolic trajectory away from the system.
Unless it doesn't have the relative velocity to escape the gravity well of the star, right?
 
  • #7
Bandersnatch
Science Advisor
2,914
1,823
Doesn't our sun rotate?
All right, if that's how you define planar, then polar orbits around a star are stable for most practical purposes. If there were any other massive bodies orbiting in the plane or solar rotation, then these would destabilise the polar orbit.

Unless it doesn't have the relative velocity to escape the gravity well of the star, right?
Consider that the planet comes from far away, from outside of gravitational influence of the star. As it falls into the gravity well it'll gain just as much velocity as it'll lose on the way out. I.e., if it was not bound to the star in the first place, then it won't become bound at all. Not without interaction with some third body.
 
  • Like
Likes Nik_2213
  • #8
990
342
All right, if that's how you define planar, then polar orbits around a star are stable for most practical purposes. If there were any other massive bodies orbiting in the plane or solar rotation, then these would destabilise the polar orbit.
I don't know another way to define it. What have I missed/

Consider that the planet comes from far away, from outside of gravitational influence of the star. As it falls into the gravity well it'll gain just as much velocity as it'll lose on the way out. I.e., if it was not bound to the star in the first place, then it won't become bound at all. Not without interaction with some third body.
I'm picturing the wanderer spiraling in to the system, not a dive in/dash out incident.
 
  • #9
Bandersnatch
Science Advisor
2,914
1,823
I don't know another way to define it. What have I missed/
No, it's all fine.

I don't know another way to define it. What have I missed/


I'm picturing the wanderer spiraling in to the system, not a dive in/dash out incident.
It can't just spiral in without a way to lose energy. If you've got a free-floating planet that encounters a lone star, then it MUST fall towards it on a hyperbolic trajectory, swing around, and leave with the same velocity relative to the star as it had at the beginning.

What you could do, is have the star begin with some planets, one or two, have the planet fall in, make a number of close encounters with the original planetary system, and as a result end up with the original planet(s) ejected and the rogue one captured.
 
  • Like
Likes Nik_2213 and hsdrop
  • #10
990
342
That would work. So it would be possible under certain circumstances... Interesting. Now to get Our Hero to figure out what's strange about the system. Thanks.
 
  • #11
1,482
161
It tends to be unstable due to Kozai resonances.
 
  • #12
Bandersnatch
Science Advisor
2,914
1,823
It tends to be unstable due to Kozai resonances.
There's no third body in this setup.
 
  • #13
990
342
Yeah, I'm thinking the system is "strangely barren" with the exception of our oddly orbiting planet.
 
  • #14
990
342
Next thing, is a star with almost no "junk" around it uncommon, unlikely, no big deal, or "never gonna happen"?
 
  • #15
324
114
Next thing, is a star with almost no "junk" around it uncommon, unlikely, no big deal, or "never gonna happen"?
well you could have a neighboring star blow up and blow most to all the junk out from around it ( just a thought)
 
  • Like
Likes Noisy Rhysling
  • #16
990
342
With so many double star sysem...
 

Related Threads on Polar solar orbit possible?

Replies
10
Views
1K
  • Last Post
Replies
8
Views
1K
  • Last Post
Replies
3
Views
3K
  • Last Post
Replies
11
Views
477
Replies
5
Views
952
Replies
5
Views
3K
Replies
9
Views
1K
Replies
6
Views
4K
Replies
7
Views
1K
Top