* Astronomy

Title: Close Binary System GO Cyg
Authors: B. Ulas, B. Kalomeni, V. Keskin, O. Kose, K. Yakut

In this study, we present long term photometric variations of the close binary system GO Cyg. Modelling of the system shows that the primary is filling Roche lobe and the secondary of the system is almost filling its Roche lobe. The physical parameters of the system are M_1 = 3.0 ±0.2 Solar masses, M_2 = 1.3 ±0.1 Solar masses, R_1 = 2.50 ±0.12 Solar radii, R_2 = 1.75 ±0.09 Solar radii, L_1 = 64 ±9 Solar luminosity, L_2 = 4.9 ±0.7 Solar luminosity, and a = 5.5 ±0.3 Solar radii. Our results show that GO Cyg is the most massive system near contact binary (NCB). Analysis of times of the minima shows a sinusoidal variation with a period of 92.3 ±0.5 years due to a third body whose mass is less than 2.3 solar masses. Finally a period variation rate of -1.4 x 10^{-9} d/yr has been determined using all available light curves.

Read more  (258kb, PDF)

Position (J2000):     R.A. 20 37 20.13010  |  Dec. +35° 26' 10.3002''