This paper obtains an approximate analytical solution for the isothermal Lane-Emden equation that models a self-gravitating isothermal sphere. The approximate solution is obtained by perturbation methods in terms of small and large distance parameters. The approximate solution is compared with the numerical solution. The approximate solution obtained is valid for all values of the distance parameter.
Soliman, Moustafa A. and Al-Zeghayer, Yousef S., "Approximate Analytical Solution for the Isothermal Lane-Emden Equation in a Spherical Geometry" (2015). Chemical Engineering. 85.