AN INTERPRETATION OF LIGHT CURVES OF SV CAMELOPARDALIS BY THE INVERSE-PROBLEM METHOD

The paper is devoted to the problem of the determination of the orbita l and physical parameters of the active eclipsing binary SV Cam on the basis of the interpretation of photometric observations made by Patko s (1982) during the period 1973-1981. The problem is solved in two sta ges: by obtaining a synthetic light curve in the case when the paramet ers of the corresponding Roche model (Djurasevic 1992a) are given a pr iori (direct problem), and by determining the parameters of the model for which the best fit between the synthetic light curve and the obser vations is achieved (inverse problem) (Djurasevic 1992b). A total of 1 8 light curves are analysed in the framework of the Roche model, invol ving one and two spotted regions on the primary component of the syste m (Sp G3 V), for the temperature contrast between the spotted area and the surrounding photosphere A(s) = T-s/T-1 = 0.65. The basic paramete rs of the system and of the spotted areas are estimated. Throughout th e whole set of the analysed light curves, a double spot model fits the observations satisfactorily. A single spot model yields a poorer fit, where the basic system parameters obtained by analysing the individua l light curves show stronger variations about a mean value. That indic ates that the single spot model cannot successfully reproduce the SV C am light curve changes during the analysed period. According to the ob tained results the spotted areas are formed at high latitudes and cove r a significant part of the stellar surface. No clear cyclicity of the system's activity is noted from the analysed observations. There are some indications that spotted areas at high latitudes (above 70 degree s) correspond to an enhanced activity. Since the system's period is sh ort (P = 0.(d)59), the presence of spotted regions at high latitudes c an be explained by the dynamo mechanism for rapid rotators (Schussler & Solanski 1992). During the analysed period the spotted areas tend to fall into a specially active longitude sectors at high latitudes, nea r stellar polar regions. Due to a selection effect it is possible that a more extensive observational material would correct this result to some extent. The light curve analysis allowed an estimation of the sys tem parameters and of the active spotted regions.