A rediscussion on the eclipsing binary YY Canis Minoris

We have reanalysed the UBV light curves of Abhyankar (1962b) using the 1993 version of Wilson-Devinney computer programme with a view to derive a cons istent solution in all the three passbands and to answer the discordant opi nions on the general picture of YY CMi. Initially, a preliminary unspotted solution was obtained and a photometric mass ratio was derived. From the pr esent analysis, we obtained a mass ratio of q = 0.89 which differs from the mass ratio of 0.8 derived by Giuricin & Mardirossian (1981) and 0.65 deriv ed by Abhyankar (1962b) but agrees with the value of 0.885 derived by Niarc hos et al. (1998). Finally, the light curves were modelled by introducing a spot on the cooler secondary component to represent the observed light cur ve asymmetries. Assuming the mass of the primary component to be 1.56 m(cir cle dot) (F1V), the absolute elements of YY CMi are found to be m(c) = 1.39 m(circle dot), R-h = 2.52 R-circle dot, R-c = 2.38 R-circle dot, Log L-h = 1.13 L-circle dot, LOg L-c = 0.86 L-circle dot, Log g(h) = 3:83 and Logg(c ) = 3.83. The primary and secondary components are found to be slightly ove rluminous and bigger in size when compared to stars of the same mass. In th e H-R diagram (log T-e versus log L, ZAMS), both the components are above b ut near the ZAMS suggesting that both of them have left the main sequence a nd have come into contact. Our results essentially agree with those of Niar chos et al. (1998) based on V passband only.