Photometric and period analysis of the eclipsing binary system V2783 Ori

. In this study we performed the first detailed photometric and period analysis of the recently discovered eclipsing binary star V2783 Ori. The analysis of the light curve has shown that the system is in a detached configuration, with the orbital eccentricity e = 0.274 ± 0.008. The photometric mass ratio of V2783 Ori determined from the light curve analysis is q = 0.734 ± 0.015. The absolute parameters of the system were obtained as a result of the light curve solution. Absolute parameters were found as follows: masses M 1 = 1.80 ± 0.01 M (cid:12) , M 2 = 1.32 ± 0.01 M (cid:12) , radii R 1 = 2.19 ± 0.10 R (cid:12) , R 2 = 1.91 ± 0.10 R (cid:12) , temperatures T 1 = 8325 ± 100 K and T 2 = 8300 ± 100 K. A comparison of these parameters with theoretical stellar models show that the secondary component is located inside the main-sequence band and still close to ZAMS, while the primary component is located in the middle of ZAMS-TAMS limits. The distance of the system determined from the absolute parameters, d = 1064 ± 150 pc, takes into account the interstellar reddening. The (O–C) diagram was discussed considering all reliable minima times found in the literature and new values for the parameters of the apsidal motion and light-time effect were found. The apsidal motion rate of V2783 Ori is ˙ ω = 0.0063 ± 0.0017 deg cycle − 1 , and it corresponds to an apsidal motion period of U = 656 ± 103 yr. The third body orbital period is 10 ± 2 yr, its minimal mass is 0.82 ± 0.11 M (cid:12) .