Close binary systems in the regions of OB-associations. IV. V698 Cygni in Cyg OB3

1Zakirov, MM, 2Eshankulova, MU
1Uzbekistan National University, 100174, Vuzgorodok, Tashkent, Uzbekistan
2Astronomical Institute, Academy of Sciences of Uzbekistan, ul. Astronomicheskaya 33, 100052, Tashkent, Uzbekistan
Kinemat. fiz. nebesnyh tel (Online) 2006, 22(1):49-57
Start Page: Physics of Stars and Interstellar Medium
Language: Russian
Abstract: 

The first UBVR photoelectric observations for the long-period eclipsing variable star V698 Cyg were carried out at the Maidanak Observatory in Uzbekistan. The total number of the measurements are 654 in U, 650 in B, 655 in V, and 646 in R. We derived a new ephemeris of the binary minima: MinI = HJD2434309.228 (33) + 97.77451(47)d \cdot E. All the light curves of the binary are solved by Lavrov's direct method and the orbit photometric elements for the system are obtained. The nature of the binary is not clear. The binary's components are considered to be stars of the A7II and KIII4 spectral types. The binary is assigned to the farthest ones of our Galaxy.

Keywords: spectral types, V698 Cyg, variable stars