Helioseismic diagnosis of the equation of state

Abstract

The helioseismic verification of major nonideal effects in the equation of state of solar matter has become well established. The dominant contribution is the Coulomb pressure, conventionally described in the Debye-Huckel approximation. Recently, the increased precesion of the helioseismic diagnosis has brought significant observational progress beyond the Debye-Huckel approximation. Obviously, progress in the equation of state serves two purposes. For solar physicists, a better equation of state will lead to reduced uncertainty in solar models. For plasma physicists, it will lead to an astrophysical experiment, in a domain where there is not much laboratory competition.