paper

Photometric Investigation of the Contact Binary GU Ori with High Metallicity

arXiv:1812.09856 · doi:10.1093/pasj/psy084

Abstract

GU Ori was observed with the 1m telescope at Yunnan Observatories in 2005. To determine its physical properties, the Wilson-Devinney program is used. The results reveal that GU Ori is a W-subtype shallow contact binary with a more massive but cooler star 2. The mass of its two component stars are estimated to be $M_{1} = 0.45 M_{⊙}$ , $M_{2} = 1.05 M_{⊙}$ . The O'Connell effect was reported to be negative on the light curves observed in 2005. However, it changed to a positive one on the light curves observed from 2011 to 2012. The mean surface temperatures of star 2 ( $T_{2}$ ) determined by the two sets of light curves were different, which may result from stellar activities. The O - C diagram shows that the period of GU Ori is decreasing at a rate of $d P / d t = - 6.24 \times 1 0^{- 8} d a y \cdot y e a r^{- 1}$ , which may be caused by mass transfer from star 2 to star 1 with a rate of $\frac{d M _{2}}{d t} = - 2.98 \times 1 0^{- 8} M_{⊙} / y e a r$ . GU Ori is a contact binary with quite high metallicity.

17 pages, 6 figures