Photometric observations of NGC 281: detection of 228 variable stars

Abstract

ABSTRACT We identify 228 periodic variables in the region of young open cluster NGC 281 using time series photometry carried out from 1 m class ARIES telescopes, Nainital. The cluster membership of these identified variables is determined on the basis of colour–magnitude, two colour diagrams, and kinematic data. A total of 81 variable stars are found to be members of the cluster NGC 281. Of 81 variables, 30 and 51 are probable main-sequence and pre-main-sequence members, respectively. This study classifies main-sequence variable stars into different variability types according to their periods of variability, shape of light curves, and location in the Hertzsprung–Russell diagram. These identified main-sequence variables could be β Cep, δ Scuti, slowly pulsating B type, and new class variables. Among 51 pre-main-sequence variables, majority of them are weak line T Tauri stars. The remaining 147 variables could belong to the field population. The variability characteristics of the field population indicate that these variables could be RR Lyrae, δ Scuti, and binaries-type variables.