Abstract Details
| Name: G. Mamatha Rani Affiliation: Department of Astronomy, Osmania University, Hyderabad Conference ID: ASI2018_1649 Title : Variable O'Connell effect and unseen third body in a Kepler binary K2 EPIC 2071279 Authors and Co-Authors : G Mamatha Rani, Sriram K., Malu S, P. Vivekananda Rao Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : We present a photometric study of Kepler binary K2 EPIC 2071279 based on ASAS, KEPLER K2 EPIC and SuperWasp data. Contact binary systems are effective astrophysical laboratories to understand the magnetic dynamo effect in stellar systems. The light curves of contact binaries exhibit an asymmetry in the maxima termed as the O'Connell effect which is considered to be a direct consequence of the spot activity, thereby the magnetic field cycle of the system. Balaji et al. (2014) performed rigorous studies of spot activity and spot migration based on the O-C analysis of 414 contact binary systems. This study revealed that the primary and secondary minima of few such systems showed anti-correlated behavior which is indicative of the longitudinal motion of starspots over the stellar surface. Based on spot migration they also concluded that ~50% of these are asynchronous with their orbits. Moreover, the O-C analysis of a system can show the secular period change of the system and its residuals can further tell us if there exists a tertiary companion for the binary. Our source presents a varying O' Connell effect along with a long term secular increase in period. The O-C diagram residual further showed the presence of LITE variations indicating the presence of a third body. We have solved the Kepler equations numerically to determine the various orbital parameters of the third body. The longtidunial cycle of the spot activity over a duration of ~13 years is discussed. |