Binary star detection in the open cluster King 1 field

Abstract

A rarely studied open cluster, King 1 is observed using the 1.3-m telescope equipped with a 2k × 4k CCD at Vainu Bappu Observatory, India. We analyze the photometric data obtained from CCD observations in both B and V bands. Out of 132 detected stars in the open cluster King 1 field, we have identified four stellar variables, and two among them are reported as newly detected binary systems. The parallax values from Gaia DR2 suggest that the open cluster King 1 is in the background of these two detected binary systems, falling along the same line of sight, giving rise to different parallax values. Periodogram analysis was carried out using Phase Dispersion Minimization (PDM) and the Lomb-Scargle (LS) method for all the detected variables. PHysics Of Eclipsing BinariEs (PHOEBE) is extensively employed to model various stellar parameters of both the detected binary systems. Based on the modeling results obtained from this work, one of the binary systems is reported for the first time as an Eclipsing Detached (ED) and the other as an Eclipsing Contact (EC) binary of W-type W UMa.