> http://www.astro.utu.fi/~cflynn/Stars/l4.html

> and I believe that I've correctly added a centripetal force term to the
> derivation of the differential equation for stellar hydrostatic
> equilibrium.  That equation relates dP/dr to d_rho/dr, where P is the
> hydrostatic pressure, rho is the mass density and r, of course, is the
> radial coordinate.  

> I added the centripetal force, rho*w^2*r, as a second body force term in
> equation (11) on that site, making that equation into

> dP/dr=rho(r)*w^2*r*sin(theta)-G*m(r)*rho(r)/r^2,

> where w is omega, the rotational frequency of the star, which is allowed to
> vary with the latitude on the star, as w=w(theta).

> The middle part is pretty much just algebra, and the answer I got was

> (1/r^2)*d[(r^2/rho)(dP/dr)]/dr+4*pi*G*rho=[3w^2+2*w*r*dw/dr]*sin(theta).

> Actually, you can tell by the presence of a dw/dr term that I allowed w to
> vary as a function of both r and theta, but I have no idea whether the is
> necessary to understand the physics, so I kept it for completeness and just
> in case.

> If I were to put in the compressible equation of state for a fluid,
> P=K*rho^gamma, my result would be an improved Lane-Emden equation.  I
> haven't done that yet, but so far it looks straightforward, and I plan to
> do it within the day or two.

> In summary, I need to know whether the above equations and derivation look
> familiar to the people in this group, and does anybody know if this
> particular approach to the problem has ever been taken before.  I have to
> know whether I have just reinvented the wheel, so I can start thinking
> about whether to get the entire derivation published, rather than just the
> first and last equations.  :b

> Any reasonable input would be greatly appreciated.  TIA.