Seismological tests of standard solar models calculated with new opacities

Autor(en)

Wojciech A. Dziembowski, Aleksiej Pamiatnych, R Sienkiewicz

Abstrakt

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(en)

Institut für Astrophysik

Externe Organisation(en)

Nicolaus Copernicus University, Polish Academy of Sciences (PAS)

Journal

Acta Astronomica: an international quarterly journal

Band

42

Seiten

5-15

Anzahl der Seiten

11

ISSN

0001-5237

Publikationsdatum

1996

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/seismological-tests-of-standard-solar-models-calculated-with-new-opacities(996ad1d7-cf98-4094-bc32-937fa7ca3370).html