INFRARED LIGHT CURVES AND SPECTROSCOPIC CLASSIFICATION OF THE ALGOL SYSTEM UX HER

We present the first light curves in the infrared J, H, and K bands of UX Her and analyze them together with published light curves in B and V in order to determine the physical parameters of the system. Based on the spectra of UX Her and standard stars in the region 8440-8870 An gstrom, we classify the primary component of the binary as a type A2-3 V star. From the absolute radii of the stars that we derive from the light-curve analysis, we find that none of the components of the binar y are filling their Roche lobes. Considering the contributions of the secondary star to the total light given by the light-curve solutions, and the measured B, V, J, H, and K magnitudes at maxima and during the eclipses, we find good agreement with those predicted from stellar at mosphere models for effective temperatures of the stellar components: T(eff,1)similar or equal to 9000 K and T(eff,2)similar to 4500 K, with the system at a distance d similar or equal to 280 pc. (C) 1997 Ameri can Astronomical Society.