Simultaneous Analysis of Light and Radial Velocity Curves of the Peculiar Contact System V 508 Ophiuchi

LAPASSET, E., GOMEZ, M.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 1990 p. 365 - 374

0004-6361

BV observations of V 508 Oph obtained between 1984 and 1987 and new times of minimum are presented. A complete study of minima published since 1943 allows to detect a likely increase of the period by about 0.003 s per year. The new versions of the Wilson-Devinney synthetic method is employed to analyze simultaneously the BV photometry and the radial velocity curves for both components of the system. Absolute values for masses, luminosities, and radii are determined in that way. The results show that V 508 Oph is a nontypical member of the A-type W UMa binaries, because of its large mass-ratio (q = 0.53) and its low degree of overcontact (about 10 percent). The striking behavior of previously observed light curves might roughly be explained by means of a blue selective emission zone located between both components of the system.