PHOTOMETRIC AND SPECTROSCOPIC ANALYSIS OF FOUR CONTACT BINARIES
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Auditorium & Online
Eclipsing binaries (EBs) are the key sources to determine stellar parameters with high precision. One interesting class of EBs is contact binary stars (CBs). These are low temperature systems with components sharing a convective envelope. Due to the contact geometry, their temperatures are almost same and mostly they show equal size primary and secondary minima. The W UMa-type CBs (EWs) are particularly interesting as these are more abundant than other type of EBs. Secondly, the closeness of components of these systems allows us to directly perceive interaction between them and their atmosphere. In this work, we present the photometric and spectroscopic analysis of four contact binaries (J0158, J0322, J1022 and KW Psc) using 1.3m DFOT (ARIES) and LAMOST. The systems J0158 and J0305 show a period increase while the analysis of J1022 shows a period decrease. The period of KW Psc is found to be constant. PHOEBE package is used for the light curve modeling and basic parameters are evaluated with the help of GAIA parallax. The asymmetry of light curves is explained with the assumption of cool spots at specific positions on one of the components of the system. All systems show some level of chromospheric activity as estimated by their spectra. The secondary components of all the systems are away from ZAMS which indicates that secondary is more evolved than the primary component.