On 9/2/12 12:40 PM, Brad Guth wrote:
Could an existing solar system like ours capture a red dwarf without
causing too much trauma for the existing planets?

If the sun encountered another star (say a red dwarf) the Keplerian
orbit of each would be hyperbolic for each star and the encounter
would be one time. Capture requires, perhaps a third star or transfer
of momentum via drag. So it very unlikely that our sun would capture
a red dwarf.