<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
<br />If a star with a radius similar to Sol's present radius were to be fed mass till it reached over spin and shed some mass, that mass would initially orbit quite close (within one or two radii ?) to Sol's surface. How far could tidal forces move such a mass?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Tidal forces are proportional to roughly the seventh power of the ratio of the star's radius to the planet's distance. For the Earth-Sun system today, that ratio is about 10^-12, and tidal forces are undetectably negligible. However, shortly after fission, that ratio could be much closer to unity and tidal forces could be huge. We have these steps:
* the new planet raises a mass bulge on the star
* the star's faster rotation carries the mass bulge ahead of the planet
* the mass bulge pulls the planet forward, increasing the planet's angular momentum
* the planet is forced into a more distant orbit
This process continues until tidal forces become negligible,
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">It makes more sense that as the planets spin off they stay fairly close to their original distance from the center of the collapsing mass. The central mass then continues to shrink, spins up again and throws off another blob or two, and so on.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">While shrinkage of the star is a big factor in the process, it cannot cause the orbits of a twin pair of fissioned planets to separate from one another. So soon after fission, tidal forces must be expanding the orbits, with the more massive planet raising the larger mass bulge and therefore evolving outward faster.
Shrinkage of the primary is more important for forming satellites. In that case, the fissioned parent planet rotates slower than the moons, so tidal forces operate to lower the orbits, and the larger-mass moon takes the inner position. Shrinkage of the planet is vital to keeping the moons outside the Roche limit.
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Has anyone done simulations on this to explore the limits of what is possible? Would the dynamics of a 1000 or 2000 AU proto star be similar to the dynamics of a 50 or 100 AU proto star? (Would a large object like this still only throw off two masses?) Or would the proto star have to go below 50 AU to begin acting like your animation?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The lack of realistic simulations is what led to my comment about what might be possible. If a proto-star is 50 AU in radius, it has a volume big enough to hold all 200 billion stars in the Galaxy. So the outer layers must be very low density, and there is obvious room for numerous loose, huge mass agglomerations to form. In a sense, this thin rotating disk is not unlike the primeval nebula invoked in conventional models. But instead of proro-planets forming anywhere in the nebula, fission theory shows that only those on the periphery can fission. -|Tom|-
