THE OPEN CLUSTER NGC-3293 AND ITS SHORT-PERIOD B-TYPE VARIABLES

We present CCD uvbybeta data for stars in the young open cluster NGC 3293. Our work significantly increases the number of stars in the cluster having Stromgren photometry, especially for the lower main sequence. We use this photometry to refine the distance modulus of the cluster. We also present results of an intensive CCD photometric survey for short-period variables. We find a new beta Cep star, bringing to 11 the total number of these variables in the cluster. All of them are confined to a narrow instability strip where no constant stars are found. One of the main objectives of this work is to detect the high-order g-mode pulsators (53 Per stars) predicted by models using the OPAL opacities on the lower main sequence. We did not find any of these stars; if such stars exist, their amplitudes are too small to detect by the techniques employed here. We found several new short-period variables: most of these are probably eclipsing binaries.