Originally Posted by j. d. worthington  Mosaix: Chris would be the one to know the more recent scientific ideas on this, but I'll take a stab at it. From my reading (admittedly several years ago), I'd say that:
Is possible, depending on how far apart the stars are. In fact, I posted a thread the other day, where they have figured out how far apart they need to be in order for the preplanetary disc to form into planetary bodies.
is highly unlikely. The gravitational stresses of such an orbit would almost certainly preclude it; the point at which the stellar gravitational attractions would meet would tend to a) prevent planets from forming in the first place or, in the highly unlikely event of such forming (or a "rogue planet" -- should such exist -- being captured), b) cause such tidal stresses that the body would break apart.
Depends on what you mean here. An oblong shape (like most race-tracks, for instance) is very unlikely, because the gravitational stresses mentioned above, where the forces of the two stars combine, would tend to tear such a body apart, should it ever have formed in the first place. On the other hand, an elliptical orbit similar to the solar system's, but enlarged to circle equidistantly from both stars, is -- again, from my understanding -- the most likely. This would be at such a distance that the disc of dust would be able to form a stable body to begin with, and where the gravity from the stars would jointly stabilize (more or less) a planetary (or series of planetary) orbit(s).
That one is also highly unlikely. The gravitational and rotational stresses applied by such would be almost certain to pull any sort of body apart, from a rocky planet to a gas giant to a smaller star -- or even one larger but less dense.
Also... don't forget that there are apparently systems which are quadruple and up, as well... These, I'd say, are unlikely to develop a planetary system... but the jury is still out on that one, I think. However, remember Asimov's "Nightfall", where the system had (as I recall) seven suns.... |