A Perturbed Tri-Polytropic Model of the Sun

Based on the Solar Standard Model SSM of Bahcall and Pinsonneault (SSM-BP2000) we developed a solar model in hydrostatic equilibrium using three polytropes, each one associated to the nuclear, the radiative and the convective regions of the solar interior. Then, we apply small periodic and adiabatic perturbations on this tri-polytropic model in order to obtain proper frequencies and proper functions which are in the p-modes range of low order 0łt}lłt}5; for l=2,3 and 4 these values agrees with GOLF observational data within a few percent.