A CCD Search for Variable Stars of Spectral Type B in the Northern Hemisphere Open Clusters. VII. NGC 1502

Abstract

We present results of variability search in the field of the young open cluster NGC 1502. Eight variable stars were discovered. Of six other stars in the observed field that were suspected for variability, we confirm variability of two, including one β Cep star, NGC 1502-26. The remaining four suspects were found to be constant in our photometry. In addition, UBV I C photometry of the wellknown massive eclipsing binary SZ Cam was obtained.The new variable stars include: two eclipsing binaries of which one is a relatively bright detached system with an EA-type light curve, an α 2 CVn-type variable, an SPB candidate, a field RR Lyr star and three other variables showing variability of unknown origin. The variability of two of them is probably related to their emission in H α , which has been measured by means of the α index obtained for 57 stars brighter than V ≈ 16 mag in the central part of the observed field. Four other non-variable stars with emission in H α were also found.Additionally, we provide V I C photometry for stars down to V = 17 mag and UB photometry for about 50 brightest stars in the observed field. We also show that the 10-Myr isochrone fits very well the observed color-magnitude diagram if a distance of 1 kpc and mean reddening, E(V − I C ) = 0.9 mag, are adopted.