Seven years photometry of the W UMa-type eclipsing binary V2612 Oph


ÖZDARCAN O. , TAŞ G.

ASTRONOMISCHE NACHRICHTEN, cilt.335, ss.833-840, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 335 Konu: 8
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1002/asna.201412113
  • Dergi Adı: ASTRONOMISCHE NACHRICHTEN
  • Sayfa Sayıları: ss.833-840

Özet

We present the first long-term Johnson UBVR observations and comprehensive photometric analysis of the W UMa-type eclipsing binary V2612 Oph. Observations in the time interval between 2003 and 2009 enabled us to reveal the seasonal and long-term variations of the light curve. Hence, we found that the mean brightness level of the light curve shows a variation with a period of 6.7 years. Maximum and minimum brightness levels of the light curve exhibit a variation from year to year which we attribute to a solar-like activity. The O - C variation of eclipse timings of the system shows a decreasing parabolic trend and reveals a period decrease at a rate of P = 6.27x10(-7) day yr(-1) with an additional low-amplitude sinusoidal variation that has a similar period as the long-term brightness variations. Our light curve analysis shows that the system is a W-subtype W UMa eclipsing binary. We calculated masses and radii of the primary and secondary components as M-1 = 1.28 M, M-2 = 0.37 M and R-1 = 1.31 R, R-2 = 0.75 R, respectively. The derived absolute photometric parameters allow us to calculate a distance of 140 pc, which confirms that the system is a foreground star in the sky field of the Galactic open cluster NGC 6633. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)