THERMODYNAMICAL PROPERTIES OF STELLAR MATTER .1. EQUATION OF STATE FOR STELLAR INTERIORS

Considering the Helmholtz free energy which provides detailed knowledg e of the charged many-particle physics, we present an analytical formu lation of the equation of state (EOS) for fully ionized matter. The no nideal effects due to exchange and correlation interactions of charged particles are described by Pade approximants, which cover a wide rang e of densities and temperatures. The formulae are valid at any electro n degeneracy, for a very broad region of Coulomb coupling, and are app licable to any chemical mixture. Relativistic generalizations are take n into account for the most predominant astrophysical conditions. Fina lly, we present results for H, He, C and O plasmas and give comparison s with other EOS approaches.