2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7274Exact and approximate analytical formulas are derived for the internal structure and global parameters of the spherical non-rotating quasi-incompressible planet. The planet is modeled by a polytrope with a small polytropic index n << 1, and solutions of the relevant differential equations are obtained analytically, to the second order of n.14 pp LaTeXAstrophysicstext