Back to Volume
Paper: A New Grid of Stellar Models until Carbon Combustion: the Tidal Braking and the Radiative Damping Constants
Volume: 333, Tidal Evolution and Oscillations in Binary Stars: Third Granada Workshop on Stellar Structure
Page: 116
Authors: Claret, A.
Abstract: We present new stellar models based on updated physics (opacities, expanded nuclear network and mass loss rates). We computed stellar models suitable for the mean solar neighborhood, i.e. for Z=0.02 and X=0.70. The covered mass range is from 0.8 up to 125 MSolar and the models are followed until the exhaustion of Carbon in the core, for the more massive ones. In addition, the effective temperatures of the more massive models are corrected for the effects of stellar winds (Wolf-Rayet stage), while models with lower effective temperatures are computed using a special treatment of the equation of state (CEFF, Däppen, private communication). Convective core overshooting, finally, is assumed to be moderate and is modelled with αOV = 0.20. Besides the classical ingredients of stellar models, we also provide the internal structure constants needed to investigate apsidal motion and tidal evolution in close binaries. The latter constants are made public for the first time. According to the current theories of tidal evolution, the time scales for synchronization and circularization for cool stars depend - apart from the mass, radius and effective temperature - on the depth of the convective envelope xbf and on the radius of gyration β1 . For stars with higher effective temperatures, these dependencies are mainly incorporated in the tidal torque constant E2. All these parameters are furthermore steep functions of mass and time, and thus require a special numerical treatment. The new mass loss formalism produces more mass concentrated configurations than previously, especially for more massive and more evolved stellar models. As the present grid is designed mainly for the study of double-lined eclipsing binaries, the gravity-darkening exponents necessary to calculate the surface brightness distribution in rotationally and/or tidally distorted stars, are computed following the method described recently by Claret (1998), and made available for each point of every evolutionary track.
Back to Volume