Photometry, period variations and light curve analysis of eclipsing binary V1191 Cyg

• We carried out new observations of the eclipsing binary V1191 Cyg and plotted light curves in BVR filters.
• We obtained 35 times of light minimum and determined new ephemeris for primary minimum of V1191 Cyg.
• We calculated and plotted O-C diagram of V1191 Cyg and calculated the period changes and mass transfer rate.
• For the first time, by using the Kalimeris method we analyzed the O-C diagram.
• We analyzed the BVR light curves and determined some geometrical and physical parameters.

New observations of the eclipsing binary system V1191 Cyg were carried out by using CCD in BVR filters and new times of light minimum and new ephemeris were obtained. For the first time, the O-C curve of this binary was analyzed by using the Kalimeris method and the orbital period and its rate of change were calculated as functions of time. The BVR   light curves were analyzed using both the Binary Maker 3.0 and PHOEBE 0.31a programs to determine some geometrical and physical parameters. By analyzing O-C diagram, the period variation was calculated to be dP/dt=3.13×10-6dyr-1 and the rate of mass transfer was Ṁc=5.23×10-7M⊙yr-1.