We present a time-series BV CCD photometry for an EB-type eclipsing binary NSVS 1908107, a member of the young open cluster NGC 869. The photometric solution was obtained by using the 2003 version of the Wilson-Devinney code. It reveals that the system is a semi-detached binary with the secondary component filling its Roche lobe. The mass ratio was determined to be 0.059±0.001. With the physical parameters of the cluster, the masses, radii and luminosities of the two components of NSVS 1908107 are estimated to be M1 = 10.34±2.29 M⊙, R1 = 4.65re±0.34 Rspectivel⊙, L1 = 8076 y. The results s±371 L = 2.40 how tha⊙and M2 = 0.61 t the secondary co±0.13M⊙, R2±0.17 R⊙, L2 = 1054±48 L⊙mponent could be a giant or subgiant star with the outer envelope being stripped.
Photometric observations of AH Cnc,a W UMa-type system in the open cluster M67,were carried out by using the 50 BiN telescope.About 100 h of time-series B- and V-band data were taken,based on which eight new times of light minima were determined.By applying the Wilson-Devinney method,the light curves were modeled and a revised photometric solution of the binary system was derived.We confirmed that AH Cnc is a deep contact(f= 51%),low mass-ratio(q = 0.156) system.Adopting the distance modulus derived from study of the host cluster,we have re-calculated the physical parameters of the binary system,namely the masses and radii.The masses and radii of the two components were estimated to be respectively 1.188(±0.061) M_☉,1.332(±0.063) R_☉ for the primary component and 0.185(±0.032) M_☉,0.592(±0.051) R_☉ for the secondary.By adding the newly derived minimum timings to all the available data,the period variations of AH Cnc were studied.This shows that the orbital period of the binary is continuously increasing at a rate of dp/dt = 4.29×10^(-10)dyr^(-1).In addition to the long-term period increase,a cyclic variation with a period of 35.26 yr was determined,which could be attributed to an unresolved tertiary component of the system.
