Solar Models: Influence of Equation of State and Opacity

Abstract

Solar models through evolutionary phases of gravitational contraction, pre-main sequence and MS phases, up to current age 4.5E9 yr. and 4.57E9 yr., were studied adopting different prescriptions for the equation of state (EOS) and different opacity tables. The results are compared with solar models we computed with different radiative opacities (Cox & Stewart 1970) and different EOS, as with models computed by other authors. Finally we provide the internal run of the thermodynamic quantities of our preferred solar model which possesses the following characteristics: age 4.50E9 yr., initial He abundance by mass 0.285, parameter of the mixing length alpha=1.82, radius and temperature at the bottom of the convective envelope are R(bottom)=0.724 Rsun and T(bottom)=2.14E6 K, respectively.