6 ms·
Okay, so as long as you have 3 or more bodies, I understand ejection. Energy gets transferred semi-randomly such that eventually one body gains too much energy
by Florin_Andrei 5y ago
Okay, so as long as you have 3 or more bodies, I understand ejection. Energy gets transferred semi-randomly such that eventually one body gains too much energy and shoots out.
But when N=2, what is the ejection mechanism? That's an elliptical orbit that should be spinning round and round forever (sans the losses via gravitational waves).
- actually_a_dog 5y agoYou mean how does the last planet get ejected? Well, that's an interesting question, actually. Because of the inherent stability of the 2 body system, the last planet gets ejected some ~50 billion years after the others. The authors' simulation takes into account the fact that a star comes close enough to the Solar System to have some tangible effect every 23M years or so. It's the cumulative effect of these stellar flybys that eventually nudges the last planet out of the system.
- Florin_Andrei 5y agoOk, external perturbation, got it. Yeah, that makes sense. Otherwise it would just very slowly spiral in, due to losses from general relativity.
- actually_a_dog 5y agoYep, and loss of angular momentum due to it being carried away by gravity waves would probably take many trillions of years, I would guess.
- ByThyGrace 5y ago> the fact that a star comes close enough to the Solar System to have some tangible effect every 23M years or so Do you have a good source that expands on this? That sounds so interesting.