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A&A Supplement Series, Vol. 125, November I 1997, 407-417

Received January 2, 1996; accepted January 20, 1997

UBV photometry and period variations of V 839 Ophiuchi gif

A. Akalin - E. Derman

Ankara University Observatory, Science Faculty, Tandogan 06100, Ankara, Turkey
e-mail: and


A complete period variation analysis and new light curves of V 839 Oph together with new ephemeris data are presented. The period variation was found to be tex2html_wrap_inline1693. The period increment indicates that the conservative mass transfer rate from the less massive component to the more massive one is tex2html_wrap_inline1695. We fitted parabolic and we discuss the possible detection of sinusoidal curves to the (tex2html_wrap_inline1697) diagram and sinusoidal oscillations with period of about tex2html_wrap_inline1699 and semi-amplitude of 0.0065 day.

A simultaneous solution of the B and V light curves was computed using the Wilson-Devinney synthetic light-curve code. The light curve solution indicates that the A-type W UMa-type system is in contact with a filling factor of tex2html_wrap_inline1707.

keywords: binaries: eclipsing -- stars: individual: V 839 Oph

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