Seismological tests of standard solar models calculated with new opacities

Author(s)
Wojciech A. Dziembowski, Aleksiej Pamiatnych, R Sienkiewicz
Abstract

We calculated models of the Sun adopting opacity data of Iglesias and Rogers (1991) for three heavy element mixtures. Calculations were made with a standard stellar evolution code ignoring effects of gravitational settling and the convective overshooting. Using nearly 2300 measured frequencies of solar p-modes we determined corrections to the sound speed and density distribution in these models. The corrections were found to be significantly smaller than those in models calculated with earlier opacities. The model calculated with the Anders and Grevesse (1989) mixture of heavy elements shows a remarkable agreement with the helioseismic data. There is, however, a contradiction between this consistency and a sizable correction to the surface helium abundance, ?Y ˜ -0.04. We argue that this large value may be a spurious result caused by inadequacies in the MHD (Mihalas, Dašppen and Hummer 1988) thermodynamics used in the models. We found new evidence for such inadequacies in relatively large corrections to the sound speed in the fractional radius range 0.85-0.95.

Organisation(s)
Department of Astrophysics
External organisation(s)
Nicolaus Copernicus University, Polish Academy of Sciences (PAS)
Journal
Acta Astronomica: an international quarterly journal
Volume
42
Pages
5-15
No. of pages
11
ISSN
0001-5237
Publication date
1996
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucris.univie.ac.at/portal/en/publications/seismological-tests-of-standard-solar-models-calculated-with-new-opacities(996ad1d7-cf98-4094-bc32-937fa7ca3370).html