b9 wrote:
this could be the case if the planets once orbited a star that died, and lost so much mass , that it's unabsorbed planets would spiral off into space and then travel in a straight line at a speed equivalent to their previous orbital velocities.
i would think that when our sun dies, that the inner planets orbital velocities would be slowed due to drag from collisions with the expanding gases that buffet them in the red giant phase before the sun has lost sufficient mass to lose the inner planets, and they would be consumed into the sun before it contracted into it's helium stage. the outer planets however, would have no mechanism that would slow their orbital velocities, and they would then exit the solar system and drift off into interstellar space when the sun dies.
i think that scenario would be common, and these newly discovered "rogue" planets are the former satellites of their dead star.
whatever, it is just my speculation. i can not provide citations or references because i just thought about it in an arm chair way (and possibly came to as valid a conclusion as an arm chair would).
Intriguing suggestion. I don't think it will happen with our solar system, though. Everything I've heard or read about the death of the sun seems to say that the planet's orbits will just expand, not actually become hyperbolic. And I'm pretty sure we've found planets around a wight dwarf before, so in some cases at least the planets can stay.
30 Nov 2011, 9:15 pm
