UBV photometry and period variations of V 839 Ophiuchi

A. Akalin; E. Derman

doi:10.1051/aas:1997232

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Volume 125 / No 3 (November I 1997)

Astron. Astrophys. Suppl. Ser., 125 3 (1997) 407-417

Abstract

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Issue		Astron. Astrophys. Suppl. Ser. Volume 125, Number 3, November I 1997


Page(s)		407 - 417
DOI		https://doi.org/10.1051/aas:1997232
Published online		15 November 1997

Astron. Astrophys. Suppl. Ser. 125, 407-417 (1997)

UBV photometry and period variations of V 839 Ophiuchi ^*

A. Akalin and E. Derman

Ankara University Observatory, Science Faculty, Tandogan 06100, Ankara, Turkey

Received: 2 January 1996
Accepted: 20 January 1997

Abstract

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 ${\rm d}P/{\rm d}t=3.1{\ }10^{-7}\,{\rm d}/{\rm yr}$ . The period increment indicates that the conservative mass transfer rate from the less massive component to the more massive one is $6.5{\ }10^{-7}\,M_{\hbox{$\odot$}}/{\rm yr}$ . We fitted parabolic and we discuss the possible detection of sinusoidal curves to the ( $\rm O-C$ ) diagram and sinusoidal oscillations with period of about $\rm 20~yr$ 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 ${\sim}39{\%}$ .

Key words: binaries: eclipsing / stars: individual: V 839 Oph

^*

Table 2 and Table 5 only available in electronic form: see the Editorial in A&AS 1994, Vol. 103, No. 1.

UBV photometry and period variations of V 839 Ophiuchi *

UBV photometry and period variations of V 839 Ophiuchi ^*