A comprehensive study of the sdB+dM binary TYC 3315-1807-1

Abstract

TYC 3315-1807-1 is an sdB+dM binary first reported by Kawka et al. (2010). Archival photometric data indicate the presence of a secondary companion causing a large reflection effect. Spectroscopic observations of the object were carried out from Vainu Bappu Observatory, Kavalur, to probe the nature of the secondary companion and to understand the post commonenvelope evolution of such objects. Spectral line equivalent widths (EW) exhibit orbital phase dependent variations, indicating the probable contribution from the secondary. A period variation study of the object was carried out using times of minima obtained from the literature and suggesting a decrease in period. The evolutionary state of the system is evaluated and discussed.