Pulsational and evolutionary analysis of the double-mode RR Lyrae star BS Com

Abstract

We derive the basic physical parameters of the field double-mode RR Lyrae star BS Com from its observed periods and the requirement of consistency between the pulsational and evolutionary constraints. By using the current solar-scaled horizontal branch evolutionary models of Pietrinferni et al. (2004) and our linear non-adiabatic purely radiative pulsational models, we get M/M(Sun) = 0.698 +/- 0.004, log(L/L(Sun)) = 1.712 +/- 0.005, T(eff) = 6840 +/- 14 K, [Fe/H] = -1.67 +/- 0.01, where the errors are standard deviations assuming uniform age distribution along the full range of uncertainty in age. The last two parameters are in a good agreement with the ones derived from the observed BVIc colours and the updated ATLAS9 stellar atmosphere models. We get T(eff) = 6842 +/- 10 K, [Fe/H] = -1.58 +/- 0.11, where the errors are purely statistical ones. It is remarkable that the derived parameters are nearly independent of stellar age at early evolutionary stages. Later stages, corresponding to the evolution toward the asymptotic giant branch are most probably excluded because the required high temperatures are less likely to satisfy the constraints posed by the colours. We also show that our conclusions are only weakly sensitive to nonlinear period shifts predicted by current hydrodynamical models.

Accepted for publication by MNRAS on 2008 February 01. The paper contains 4 figures and 8 tables

References in corpus (24)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Hubble Space Telescope Fine Guidance Sensor Parallaxes of Galactic Cepheid Variable Stars: Period-Luminosity Relations
• Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case of TrES-2
• Effective temperature scale and bolometric corrections from 2MASS photometry
• A new calibration of Galactic Cepheid Period-Luminosity relations from B to K bands, and a comparison to LMC PL relations
• Cepheid Parallaxes and the Hubble Constant
• The effect of metallicity on the Cepheid Period-Luminosity relation from a Baade-Wesselink analysis of Cepheids in the Galaxy and in the Small Magellanic Cloud
• The composition of HB stars : RR Lyrae variables
• Fourier decomposition and frequency analysis of the pulsating stars with P < 1day in the OGLE database. II. Multiperiodic RR Lyrae variables in the Galactic Bulge
• Empirical relations for cluster RR Lyrae stars revisited
• MOST photometry of the RRd Lyrae variable AQ Leo: Two radial modes, 32 combination frequencies, and beyond
• Automated Nonlinear Stellar Pulsation Calculations: Applications to RR Lyrae stars. The Slope of the Fundamental Blue Edge and the First RRd Model Survey
• A delta Scuti distance to the Large Magellanic Cloud
• Nonlinear Beat Cepheid Models
• uvbyCaHbeta CCD Photometry of Clusters. III. The Most Metal-Rich Open Cluster, NGC 6253
• On the double-mode RR Lyrae variables of the Sculptor dwarf galaxy
• Beat Cepheids as Probes of Stellar and Galactic Metallicity
• Consistent distances from Baade-Wesselink analyses of Cepheids and RR Lyraes
• Double-Mode Stellar Pulsations
• On the incidence rate of first overtone Blazhko stars in the Large Magellanic Cloud
• Studying Blazhko RR Lyrae stars with the 24-inch telescope of the Konkoly Observatory
• New pulsational properties of eight "anomalous" RR Lyrae variables
• The double-mode RR Lyrae variable BS Com

Cited by in corpus (6)

• New RR Lyrae variables in binary systems
• Study of Globular Cluster M53: new variables, distance, metallicity
• Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars
• Probing galactic double-mode RR Lyrae stars against Gaia EDR3
• Toward more accurate RR Lyrae metallicities
• Fundamental parameters of RR Lyrae stars from multicolour photometry and Kurucz atmospheric models -- II. Adaptation to double-mode stars