Probing the models: Abundances for high-mass stars in binaries
arXiv:1312.5261 · doi:10.1051/eas/1364004
Abstract
The complexity of composite spectra of close binary star system makes study of the spectra of their component stars extremely difficult. For this reason there exists very little information on the photospheric chemical composition of stars in close binaries, despite its importance for informing our understanding of the evolutionary processes of stars. In a long-term observational project we aim to fill this gap with systematic abundance studies for the variety of binary systems. The core of our analysis is the spectral disentangling technique, which allows isolation of the individual component star spectra from the time-series of observed spectra. We present new results for high-mass stars in close binaries. So far, we have measured detailed abundances for 22 stars in a dozen detached binary systems. The parameter space for the stars in our sample comprises masses in the range 8--22 M_sun, surface gravities of 3.1--4.2 (c.g.s.) and projected rotational velocities of 30--240 km/s. Whilst recent evolutionary models for rotating single stars predict changes in photospheric abundances even during the main sequence lifetime, no star in our sample shows signs of these predicted changes. It is clear that other effects prevail in the chemical evolution of components in binary stars even at the beginning of their evolution.
8 pages, 3 figures, to appear in the proceedings of the conference on 'Setting a New Standard in the Analysis of Binary Stars', K. Pavlovski, A. Tkachenko and G. Torres, eds., EAS Publication Series
References in corpus (8)
- Binary interaction dominates the evolution of massive stars
- Pre-Supernova Evolution of Massive Single and Binary Stars
- Rotational mixing in massive binaries: detached short-period systems
- The VLT-FLAMES survey of massive stars: constraints on stellar evolution from the chemical compositions of rapidly rotating Galactic and Magellanic Cloud B-type stars
- Nitrogen enrichment, boron depletion and magnetic fields in slowly-rotating B-type dwarfs
- Constraints on rotational mixing from surface evolution of light elements in massive stars
- Chemical evolution of high-mass stars in close binaries. I. The eclipsing binary V453 Cygni
- Mixing of CNO-cycled matter in massive stars