Accession Number : AD0613587

Title :   THE EFFECTS OF RADIATIVE BRAKING ON FREE PERIODS OF STELLAR PULSATIONS,

Corporate Author : BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH

Personal Author(s) : Kopal,Zdenek

Report Date : JAN 1965

Pagination or Media Count : 25

Abstract : The virial theorem generalised to include the effects of interaction of matter with radiation in stellar interiors is invoked to evaluate the influence of such effects on the fundamental mode of free periods of radial oscillations; and two types of solution are considered in some detail: one of purely harmonic oscillations with phase-lag; the other oscillating in phase throughout the interior, but with complex frequency. It is shown that, in both cases, the interaction terms in the virial theorem introduce the luminosity L of the respective configuration explicitly in the equation for the period, in such a manner as to make the latter increase with L. The quantitative effects of such influence are found to be negligible for configurations of moderate density concentration, and could become appreciable only if this concentration were to become very high. Moreover, the fact that the real art of complex frequency turns out to be positive opens a possibility for the outward flux of radiation to feed energy into radial oscillations of the stars to give them a start if (and only if) the central condensation of such a configuration is sufficiently high. (Author)

Descriptors :   (*EQUATIONS OF STATE, STARS), (*STARS, EQUATIONS OF STATE), (*ASTROPHYSICS, STARS), OSCILLATION, GASES, SPHERES, THERMODYNAMICS, LUMINESCENCE

Distribution Statement : APPROVED FOR PUBLIC RELEASE