Photometric Study of the Open Cluster NGC 3293

G. BAUME; R.A VÁZQUEZ; A. FEINSTEIN

Tonantzintla, Mexico

Congreso; IX Latin American Regional IAU Meeting; 1998

The open cluster NGC 3293 has been observed with broad band UBVRI CCD photometry up to V = 19 mag. We have found evidences that the cluster is seeing through regions with different absorptions. One of them with E(B-V) = 0.31 and the other, placed in the south-east, with E(B-V) = 0.45. This new photometry locates the cluster at a distance d = 2600 pc (Vo - Mv = 12.1). The reddening law in the direction to NGC 3293 is normal apparently. Its age, however, is 6.3x10^6 yr when fitting its brightest members with modern isochrones computed with mass loss and overshooting, but it ranges from 10 to 16x10^6 yr if the less massive stars are fitted with PMS isochrones. We also see some probable pre-main sequence stars with ages of about 3x10^6 yr. All this gives evidences against coevallity. After removing the field star contribution (using a comparison frame) we could calculate the slope of both, the luminosity and mass function of the most massive members.