[Previous] | [Session 76] | [Next]

[76.06] The Double-Lined Spectroscopic Binary G209-35: Testing Stellar Evolution Models

M. Pan (MIT), G. Torres, D. W. Latham (Harvard-Smithsonian CfA)

A new spectroscopic orbit was derived for the double-lined binary G209-35 (HD 195987) based on 52 spectra taken over the past 16 years. An orbital inclination of \makebox[0in][l]{90.}90^\circ2 ± \makebox[0in][l]{6.}6^\circ0 was derived for G209-35 from the Hipparcos intermediate results; the new orbit and this inclination yielded component masses of 0.7907 ±0.0143 M_\odot and 0.6297 ±0.0069 M_\odot. Comparison of the G209-35 components to recent stellar isochrones and evolutionary tracks showed some disagreement between the models and the G209-35 data. In particular, the magnitude difference between the G209-35 primary and secondary was consistently larger than the models' predictions for stars of the derived masses. Outside of this, the G209-35 data were in closest agreement with interpolations of models computed by Baraffe et al. (1997).