Abstract Details

Name: Alaxender Panchal
Affiliation: Aryabhatta Research Institute of Observational Sciences
Conference ID: ASI2021_368
Title : PHOTOMETRIC AND SPECTROSCOPIC ANALYSIS OF FOUR CONTACT BINARIES
Authors and Co-Authors : Alaxender Panchal (ARIES) Dr. Y. C. Joshi (ARIES)
Abstract Type :
Abstract Category : Stars, ISM and Galaxy
Abstract : We present the photometric and spectroscopic analysis of four W UMa binaries CRTSJ015829.5+260333, CRTSJ030505.1+293443, CRTSJ102211.7+310022 and KW Psc. The VRI-band photometric observations are carried out with the 1.3-m Devasthal Fast Optical Telescope (DFOT). For low resolution spectroscopy, we used the 2-m Himalayan Chandra Telescope (HCT) as well as the archival data from 4-m LAMOST survey. The systems J0158 and J0305 show a period increase rate of 5.26x10^-7 days/yr and 1.78x10^-6 days/yr. The period of J1022 is found to be decreasing with a rate of 4.22x10^-6 days/yr. The period analysis of KW Psc by showss no change in period. We have used PHOEBE package for the photometric light curve modeling and the basic parameters like luminosity, mass and radius of the components are evaluated with help of GAIA parallax. The asymmetry of light curve maxima at phase -0.25 and 0.25 is explained with the assumption of cool spots at specific positions on one of the components of the system. On the basis of temperatures, mass ratios, fill-out factors and periods, we identify J0305, J1022 and KW Psc as W-subtype systems. The J0158 is most likely to be A-subtype system. To probe the chromospheric activities in these W UMa binaries, H_alpha, H_beta and Ca triplet lines are compared with the known inactive stars of same spectral type using spectral subtraction technique. The subtracted spectra shows emission in these lines. To understand the evolutionary status of these systems, the components are plotted in mass-radius and mass-luminosity planes with other well characterized binary systems. The secondary components of all the systems are away from ZAMS which indicates that secondary is more evolved than the primary component.