[TML] Planets in binary systems

[Jerry W Barrington]

Planets can orbit far from a pair of stars, or close to either of the stars.
"Close" is often quoted as about 1/3 of the way to the other star.  A useful
rule of thumb, but it assumes the stars are equal mass.  Obviously, if one
is much less massive than the other, it's planets must be much closer in.
This is why Jupiter can't have moons 1.7 AU out!  (Even if there weren't
other planets affecting things)

I think a more accurate figure would be 1/2 of the way to the nearest
Lagrange point, at their closest approach.  Unfortunately, I can't seem to
find simple equations for the locations of of L1/2/3 for arbitrary masses.
:(

I tried looking at the Hill sphere too, but all the online info I can find
on Hill and Lagrange assume one mass much greater than the other.  Any
suggestions where I could find more general equations?  Or even an easy
derivation?  :)