Observation and Light Curve Analysis of Three Eclipsing Dwarf Novae

摘要

We present the results of our photometric observations of the eclipsing dwarf novae V1239 Her, V2051 Oph, and EX Dra in quiescence. All light curves exhibit a deep main eclipse, a depression near the secondary minimum, and a hump before the eclipses. However, the light curves can vary from cycle to cycle. We have improved the orbital period of V1239 Her using the O - C diagram over a long time interval. The combined "hot line + hot spot" model was used to analyze the light curves of V1239 Her. Some physical and geometrical parameters of the components, such as the temperature of inner and outer disk and the hot spot, have been derived.