NSVS 1908107, an EB-type eclipsing binary in the open cluster NGC 869

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 = 4.65±0.34 R_⊙, L₁ = 8076±371 L_⊙ and M₂ = 0.61±0.13 M_⊙, R₂ = 2.40±0.17 R_⊙, L₂ = 1054±48 L_⊙ respectively. The results show that the secondary component could be a giant or subgiant star with the outer envelope being stripped.