Marginally low mass ratio close binary system V1191 Cyg

• Published in: New astronomy 2012, Vol.17 (1), p.46-49
• Main Authors: Ulaş, B., Kalomeni, B., Keskin, V., Köse, O., Yakut, K.
• Format: Article
• Language: English
• Subjects: Stars: binaries: close; Stars: binaries: eclipsing; Stars: fundamental parameters; Stars: individual: V1191 Cyg
• ISSN: 1384-1076; 1384-1092
• DOI: 10.1016/j.newast.2011.06.002

► The light and radial velocity curves of V1191 Cyg are solved simultaneously. ► The orbital and physical parameters of the system are determined. ► New observations indicate a very high mass transfer rate between the components. ► New observations show that the depths of the minima of the light curve have been interchanged. In this study, we present photometric and spectroscopic variations of the extremely small mass ratio ( q ≃ 0.1) late-type contact binary system V1191 Cyg. The parameters for the hot and cooler companions have been determined as M h = 0.13 (1) M ⊙, M c = 1.29 (8) M ⊙, R h = 0.52 (15) R ⊙, R c = 1.31 (18) R ⊙, L h = 0.46 (25) L ⊙, L c = 2.71 (80) L ⊙, the separation of the components is a = 2.20 (8) R ⊙ and the distance of the system is estimated as 278 (31) pc. Analyses of the times of minima indicates a period increase of dP dt = 1.3 ( 1 ) × 10 - 6 days / yr that reveals a very high mass transfer rate of dM dt = 2.0 ( 4 ) × 10 - 7 M ⊙ / yr from the less massive component to the more massive one. New observations show that the depths of the minima of the light curve have been interchanged.