Current options for the equation of state of the solar interior.
Abstract
The principal open problem of the equation of state is the number of excited states of hydrogen and helium in the zones of partial ionization. The number of excited states is affected in two ways: first by destruction of the levels due to the (neutral and charged) surrounding species, and second by statistical mechanics which governs the population of the available levels. The author discusses recent progress in this field and explains the two principal current "philosophies". One is the chemist's view, in which bound systems are interpreted as autonomous species with reactions between each other, the other is the physicist's view, in which a virial expansion of pressure is obtained starting out from fundamental species only (i.e. electrons and nuclei), and in which the socalled PlanckLarkin partition function appears.
 Publication:

Seismology of the Sun and SunLike Stars
 Pub Date:
 December 1988
 Bibcode:
 1988ESASP.286..451D
 Keywords:

 Equations Of State;
 Helioseismology;
 Solar Interior;
 Stellar Models;
 Excitation;
 Mathematical Models;
 Partitions (Mathematics);
 Solar Physics;
 Solar Physics;
 Solar Interior: Equation of State