Photometric and Spectroscopic Study of Ten Low Mass Ratio Contact Binary Systems:Orbital Stability,O'Connell Effect and Infrared Calcium Line Filling  

作　　者：Surjit S.Wadhwa Adam Popowicz Raúl Michel Petar Kostić Oliver Vince Nick F.H.Tothill Ain Y.De Horta Miroslav D.Filipović 

机构地区：[1]School of Science,Western Sydney University,Locked Bag 1797,Penrith,NSW 2751,Australia [2]Department of Electronics,Electrical Engineering and Microelectronics,Silesian University of Technology,Akademicka 16,44120 Gliwice,Poland [3]Instituto de Astronomía,UNAM.A.P.877,22800 Ensenada,BC,México [4]Astronomical Observatory,Volgina 7,11060 Belgrade,Serbia

出　　处：《Research in Astronomy and Astrophysics》2024年第8期212-222,共11页天文和天体物理学研究（英文版）

基　　金：support by the Astronomical station Vidojevica,funding from the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(contract No.451-03-66/2024-03/200002);by the EC through project BELISSIMA(call FP7-REGPOT-2010-5,No.265772);financed by Silesian University of Technology Statutory Activities grant No.BK-250/RAu-11/2024。

摘　　要：Low mass ratio contact binary systems are more likely to have unstable orbits and potentially merge.In addition,such systems exhibit characteristics such as starspots and high energy emissions(UV)suggestive of chromospheric and magnetic activity.Light curve modeling of ten contact binary systems is reported.All were found to be of extreme low mass ratio ranging from 0.122 to 0.24 and three were found to be potentially unstable and possible merger candidates.Filling of the infrared calcium absorption lines is a marker of increased chromospheric activity.We use the available Large Sky Area Multi-Object Fiber Spectroscopic Telescope spectra along with matched standard spectra(broadened for rotation)to measure the excess filling of the central core depression flux of the two main infrared calcium absorption linesλ8542 andλ8662.We find that all reported contact binaries have excess filling of the core flux in the infrared calcium lines.Three of the systems reported were also observed by the Galaxy Evolution Explorer mission and we find that all three have features of excess ultraviolet emissions further adding evidence for increased chromospheric activity in low mass ratio contact binaries.Analysis of both orbital stability and absorption line filling is dependent on the determination of geometric and absolute parameters from light curve modeling.Not an insignificant number of contact binary light curves exhibit the O’Connell effect,usually attributed to starspots.We discuss the inclusion of starspots in light curve solutions and how they influence the geometric and absolute parameters.

关 键 词：(stars)binaries eclipsing-techniques photometric-stars chromospheres 

分 类 号：P15[天文地球—天文学]