Search for short-period variable stars in the open cluster NGC 2301

¹ Korea Astronomy Observatory, Taejon, 305-348, Korea
² Department of Earth Science, Pusan National University, Pusan, 609-735, Korea
³ Astronomy Program, SEES, Seoul National University, Seoul, 151-742, Korea

Corresponding author: S.-L. Kim, slkim@kao.re.kr

Received: 28 June 2000
Accepted: 13 March 2001

Abstract

Time-series CCD photometric observations of an intermediate age open cluster NGC 2301 were performed to search for variable stars, particularly γ Dor stars and δ Sct stars. We also carried out UBVI photometry to study physical properties of variable stars in the cluster. We derived observational parameters of the cluster from UBVI photometric results. The best fit of the empirical ZAMS in a color-color diagram gives a reddening value of . We also estimated a distance modulus of and an age of , from the ZAMS and isochrone fitting in a color-magnitude diagram. Using V time-series data, we carefully examined light variations of 923 stars fainter than 100, and discovered nine short-period variable stars; two γ Dor candidates, five eclipsing binaries, one Slowly Pulsating B star and one magnetic Chemically Peculiar variable candidate. Two γ Dor candidates with relatively short periods of around 0.3 days are located in a redder region (about 01 in color) than the red edge of δ Sct instability strip in the color-magnitude diagram.