Fundamental parameters of RR Lyrae stars from multicolour photometry and Kurucz atmospheric models - I. Theory and practical implementation
Abstract
A photometric calibration of Kurucz static model atmospheres is used to obtain the following parameters of RR Lyrae stars: variation of stellar angular radius ϑ, effective temperature Te, gravity ge as a function of phase, interstellar reddening E(B - V) towards the star and atmospheric metallicity M. Photometric and hydrodynamic conditions are given to find the phases of pulsation when the quasi-static atmosphere approximation (QSAA) can be applied. The QSAA is generalized to a non-uniformly moving spherical atmosphere, and the distance d, mass and atmospheric motion are derived from the laws of mass and momentum conservation. To demonstrate the efficiency of the method, the UBV(RI)C photometry of SU Dra was used to derive the following parameters: [M] = -1.60 +/- 0.10 dex, , equilibrium luminosity Leq = 45.9 +/- 9.3 Lsolar andTeq = 6813 +/- 20 K.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2010
- DOI:
- arXiv:
- arXiv:1003.4445
- Bibcode:
- 2010MNRAS.406..486B
- Keywords:
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- hydrodynamics;
- stars: atmospheres;
- stars: fundamental parameters;
- stars: individual: SU Dra;
- stars: oscillations;
- stars: variables: RR Lyrae;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- This submission has been withdrawn by arXiv administrators because it is a duplicate of arXiv:1007.3441, which is the published version