Publications of the Astronomical Society of the Pacific
108: 332-337, 1996 April

           Photometric Analyses of the Short-Period Contact Binaries
                    HY Pavonis, AW Virginis, and BP Velorum

               EMILIO LAPASSET, MERCEDES GOMEZ, AND RAUL FARINAS

   Observatorio Astronomico de Cordoba, Laprida 854, 5000 Cordoba, Argentina
        Electronic mail: lapasset@uncbob.edu.ar, mergom@uncbob.edu.ar,
                            rfarinas@uncbob.edu.ar

     ABSTRACT.  We present BV light-curve synthetic analyses of three
     short-period contact (W UMa) binaries: HY Pavonis (P =~ 0.35 days), AW
     Virginis (P =~ 0.35 days), and BP Velorum (P =~ 0.26 days).  Different
     possible configurations for wide range of the mass ratio were explored
     in each case making use of the Wilson-Devinney code.  The photometric
     parameters of the systems were determined from the synthetic
     light-curve solutions that best fit the observations.  AW Vir has two
     components of very similar temperatures and therefore the subtype (A
     or W) remains undetermined.  HY Pav and BP Vel are best modeled by
     W-type configurations and the asymmetries in the light curves are
     reproduced by introducing cool spots on the more massive secondary
     components.  Although BP Vel lies in the region of the open cluster Cr
     173, its distance modulus, in principle, rules it out as a cluster
     member.