BVR photometry of IZ Mon and AR Dra

By the aid of the updated W-D analysis code, the photometric solutions were deduced from the multi-color light curves (LCs). IZ Mon is a semi-detached binary with a mass ratio of q=0.388(+/-0.002) , while AR Dra is a detached star with a mass ratio of q=0.652(+/-0.002).

The asymmetric LCs of IZ Mon were modeled by a hot spot on the secondary's surface, which may be attributed to mass transfer from the primary. Based on all collected eclipse times for two systems, we constructed their timing residual curves. The orbital period for IZ Mon may be continuously decreasing at a rate of dP/dt=-2.06(+/-0.04)days/yr, which may result from mass and angular momentum loss from the central system.