EDP Sciences
Free Access
Volume 438, Number 2, August I 2005
Page(s) 653 - 660
Section Stellar structure and evolution
DOI https://doi.org/10.1051/0004-6361:20052902

A&A 438, 653-660 (2005)
DOI: 10.1051/0004-6361:20052902

Inferences from pulsational amplitudes and phases for multimode $\delta$ Sct star FG Vir

J. Daszynska-Daszkiewicz1, 2, W. A. Dziembowski2, 3, A. A. Pamyatnykh2, 4, 5, M. Breger5, W. Zima5 and G. Houdek6

1  Astronomical Institute, Wroclaw University, ul. Kopernika 11, 51-622 Wroclaw, Poland
    e-mail: daszynska@astro.uni.wroc.pl
2  Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland
3  Warsaw University Observatory, Al. Ujazdowskie 4, Warsaw, Poland
4  Institute of Astronomy, Russian Academy of Science, Pyatnitskaya 48, 109017 Moscow, Russia
5  Institute of Astronomy, University of Vienna, Türkenschanzstr. 17, 1180 Vienna, Austria
6  Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK

(Received 18 February 2005 / Accepted 29 March 2005)

We combine photometric and spectroscopic data on twelve modes excited in FG Vir to determine their spherical harmonic degrees $\ell$, and to obtain constraints on the star model. The effective temperature consistent with the mean colours and the pulsation data is about 7200 K. In six cases, the $\ell$ identification is unique with above 80% probability. Two modes are identified as radial. Simultaneously with $\ell$, we determine a complex parameter f which probes subphotospheric stellar layers. Comparing its values with those derived from models assuming different treatment of convection, we find evidence that convective transport in the envelope of this star is inefficient.

Key words: stars: oscillations -- $\delta$ Scuti -- stars: fundamental parameters -- convection

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© ESO 2005