V/(V−I) CMD for the clustered YSOs identified by Koenig et al. (2008) in the cluster region. The continuous line is the isochrone of 4 Myr from Girardi et al. (2002) and the dashed lines are the 0.1-, 1- and 5-Myr PMS isochrones from Siess et al. (2000). The isochrones are corrected for the cluster distance of 2.1 kpc and reddening E(B−V) = 0.62 mag.