V839 Cep - a new massive eclipsing variable with apsidal motion in the field of Trumpler 37

Our precise UBV photometric light curves of a poorly studied Algol-type eclipsing binary V839 Cep were used to derive relative and absolute parameters of the system. The masses of the components 3.3 +/- 0.2 M-circle dot, 4.4 +/- 0.3 M-circle dot, radii 1.9 +/- 0.1 R-circle dot, 2.9 +/- 0.1 R-circle dot, effective temperatures 14150 +/- (300) K, 15700 +/- (300) K and inclination of the orbit 88.15 +/- 0.02 deg were determined. The Eclipse Time Variation (ETV) diagram revealed the apsidal motion in the system with (omega) over dot(obs) = 0.027(9)deg yr(-1), U = 13600(4500) years.