INVESTIGATION OF THE SEMIDETACHED ECLIPSING BINARY RZ-DRACONIS

New B and V photoelectric observations gathered in the years 1989-1990 are presented. An analysis of the two-colour light curve using the Wi lson-Devinney code indicates that the system is semidetached. The phot ometric mass ratio of the system RZ Dra is found to be q=0.45 and its inclination i=87-degrees. The secondary, less massive and less luminou s component fills its critical Roche lobe, while the primary one is sl ightly below. Using the spectroscopic value of the mass function and t he parameters resulting from the light curve synthesis, the following masses and radii of components of RZ Dra are estimated: M1=1.40M., M2= 0.62M., R1=1.62R., R2=1.12R.. Period changes of the system are also di scussed.