Effects of Opacity on Stellar Radii and Their Relevance to Observational Data

Authors : Gülay İNLEK, Aysun BÖKE, Oktay YILMAZ, Edwin BUDDING

Pages : 65-78

Doi:10.3906/tar-1207-72

View : 18 | Download : 10

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :We have examined the effect of varying opacities on envelope structure with the aid of Paczynski`s public domain stellar modelling programs. For this, we prepared new opacity tables from the data of Kurucz [1], using Lagrange interpolation to obtain the tabular values. We compare the results of these Kurucz opacities with similar tabulations from Huebner et al. [2], Iglesias and Rogers [3], Rogers and Iglesias [4] and Iglesias and Rogers [5]. We have checked calculations for the same ranges of stars considered originally by Schwarzschild [6], and compared our findings, using newer opacity data, with those of other sources. We consider how such calculations relate to high accuracy observational data, with the well-observed planetary eclipsing system V 376 Peg insert ignore into journalissuearticles values(HD 209458);, providing a guideline towards data of similar accuracy in the near future. Current accuracies on absolute radii and masses derivable from eclipsing spectroscopic binaries are conservatively estimated at \sim 1%. The effects of revised opacity calculations on the radii of stars of intermediate mass are several times greater than this insert ignore into journalissuearticles values(5-10% for constant values of other parameters);, so that eclipsing binary data should have good potential for independent tests of opacity theory across a wide range of stellar types.
Keywords : Stars general structure modelling, opacity tables, observational tests, eclipsing binary data