EDP Sciences
Free access
Volume 398, Number 2, February I 2003
Page(s) 677 - 685
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20021679

A&A 398, 677-685 (2003)
DOI: 10.1051/0004-6361:20021679

A photometric mode identification method, including an improved non-adiabatic treatment of the atmosphere

M.-A. Dupret1, J. De Ridder2, P. De Cat2, C. Aerts2, R. Scuflaire1, A. Noels1 and A. Thoul1

1  Institut d'Astrophysique et de Géophysique de l'Université de Liège, allée du 6 Août 17, 4000 Liège, Belgium
2  Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200, 3001 Leuven, Belgium

(Received 17 September 2002 / Accepted 7 November 2002)

We present an improved version of the method of photometric mode identification of Heynderickx et al. (1994). Our new version is based on the inclusion of precise non-adiabatic eigenfunctions determined in the outer stellar atmosphere according to the formalism recently proposed by Dupret et al. (2002a). Our improved photometric mode identification technique is therefore no longer dependent on ad hoc parameters for the non-adiabatic effects. It contains the complete physical conditions of the outer atmosphere of the star, provided that rotation does not play a key role. We apply our method to the two slowly pulsating B stars HD 74560 and HD 138764 and to the $\beta$ Cephei star EN (16) Lac. Besides identifying the degree  $\ell$ of the pulsating stars, our method is also a tool for improving the knowledge of stellar interiors and atmospheres, by imposing constraints on parameters such as the metallicity and the mixing-length parameter  $\alpha$ (a procedure we label non-adiabatic asteroseismology).

Key words: stars: oscillations -- stars: atmospheres -- stars: variables: general

Offprint request: M.-A. Dupret, madupret@ulg.ac.be

SIMBAD Objects

© ESO 2003