...the red giant is slowed by an equal amount (speaking of momentum, of course). This means you must disregard velocity effects caused by gravitational interaction between the two bodies, prior to impact.
Look, there's an easy way to figure this: for a red dwarf to achieve that velocity, then there must have been very many objects hitting it that were traveling faster than it, and in the same direction that it is now traveling. If you want to postulate that it was hit by masses that were half of its total mass, then they must have been traveling twice its speed. Both those suppositions are kooky: 1) a red dwarf hit by gas giants totaling half its starting mass probably would not look like a red dwarf any more (and it would be amazingly unlucky to attract all those collisions), and 2) this guy is trucking! how did all these gas giants get to be traveling twice as fast as it is (and all aimed in the right direction).
Space/Science » in reply to Yes, by conservation of momentum and relative speed.
to the extent that a body is accelerated by falling into a red dwarf...
The whole thread (29 posts)
- From GALEX: Speeding-Bullet Star Leaves Enormous Streak Across Sky
- Speed due to planetary impacts?
- no: conservation of momentum - relative masses. (n/t)
- Yes, by conservation of momentum and relative speed.
- No
- to the extent that a body is accelerated by falling into a red dwarf...
- re: to the extent that a body is accelerated by falling into a red dwarf...
- Yes, by conservation of momentum and relative speed.
- no: conservation of momentum - relative masses. (n/t)
- My local affiliates...
- re: From GALEX: Speeding-Bullet Star Leaves Enormous Streak Across Sky
- re: From GALEX: Speeding-Bullet Star Leaves Enormous Streak Across Sky. - Of course a 'bow shock' is seen. (n/t)
- Speed due to planetary impacts?