Close binary systems in regions of OB-Associations. III. V443 Cygni in Cyg OB9

1Zakirov, MM, 2Eshankulova, MU
1Uzbekistan National University, 100174, Vuzgorodok, Tashkent, Uzbekistan
2Astronomical Institute, Academy of Sciences of Uzbekistan, ul. Astronomicheskaya 33, 100052, Tashkent, Uzbekistan
Language: eng
Abstract: 

&Physics of Stars and Interstellar Medium BRussian Kvariable stars, close binary system, OB-association// The first UBVR photoelectric observations for the eclipsing variable star V433 Cyg are carried out at the Maidanak Observatory in Uzbekistan. A new ephemeris of the binary (MinI HJD2452115.2316(38) + 1.66220545(43) ⋅ E) is derived. A new period is twice as large as that determined earlier. The ephemeris harmonic term detected before is not found. The harmonic small-amplitude osculation with a period of 1.0481 d for outside eclipsing phases is detected. All the light curves of the binary are solved by Lavrov's direct method and the orbit photometric elements for the system are derived. The expected absolute basic parameters for the components of V433 Cyg are estimated: M1 = 3.2M, M2 = 2.5M, R1 = 2.3R, R2 = 1.8R, M1,bol = -0.3m, M2,bol = 0.7m. We suppose that V433 Cyg is a PMS binary at the near ZAMS and belongs to the OB-association Cyg OB9.

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