Photometric investigation on the W-subtype contact binary V1197 Her

作     者：Xiao Zhou Boonrucksar Soonthomthum Xiao Zhou;Boonrucksar Soonthornthum

作者机构：Yunnan ObservatoriesChinese Academy of SciencesKunming 650216China National Astronomical Research Institute of Thailand260 Moo 4T.DonkaewA.MaerimChiangmai50180Thailand Key Laboratory of the Structure and Evolution of Celestial ObjectsChinese Academy of SciencesKunming 650216China Center for Astronomical Mega-ScienceChinese Academy of SciencesBeijing 100101China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2020年第20卷第1期

页      面：77-82页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11703080 and11703082) the Yunnan Natural Science Foundation(No.2018FB006) 

主　　题：techniques:photometric binaries:eclipsing stars:fundamental parameters 

摘      要：Multi-color light curves of V1197 Her were obtained with the 2.4 meter optical telescope at the Thai National Observatory and the Wilson-Devinney(W-D)program was used to model the observational light *** photometric solutions reveal that V1197 Her is a W-subtype shallow contact binary system with a mass ratio of q=2.61 and a fill-out factor of f=15.7%.The temperature difference between the primary star and secondary star is only 140 K in spite of the low degree of contact,which means that V1197 Her is not only in geometrical contact configuration but is also already under thermal contact *** orbital inclination of V1197 Her is as high as i=82.7?,and the primary star is completely eclipsed at the primary *** totally eclipsing characteristic implies that the determined physical parameters are highly *** masses,radii and luminosities of the primary star(star 1)and secondary star(star2)are estimated to be M1=0.30(1)M⊙,M2=0.77(2)M⊙,R1=0.54(1)R⊙,R2=0.83(1)R⊙,L1=0.18(1)L⊙and L2=0.38(1)L⊙.The evolutionary statuses of the two component stars are drawn in the Hertzsprung-Russell diagram,showing that the less massive but hotter primary star is more evolved than the secondary *** period of V1197 Her is decreasing continuously at a rate of d P/dt=-2.58×10^-7 day·year^-1,which can be explained by mass transfer from the more massive star to the less massive one at a rate of dM2/dt=-1.61×10^-7 M⊙year^-*** light curves of V1197 Her are reported to show the O’Connell ***,a cool spot is added to the more massive star to model the asymmetry in the light curves.