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Seven years photometry of the W UMa‐type eclipsing binary V2612 Oph
Author(s) -
Özdarcan O.,
Taş G.
Publication year - 2014
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.201412113
Subject(s) - light curve , physics , astrophysics , photometry (optics) , brightness , variation (astronomy) , sky , binary number , amplitude , contact binary , binary star , astronomy , stars , optics , mathematics , arithmetic
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 = 6.27×10 ‐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. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)