A comprehensive study of the young open star cluster NGC 6611 based on deep VRI CCD images and 2MASS data

摘要

In the present study, we have used Deep CCD images of the extremely young open star cluster NGC 6611, up to a limiting magnitude of V ～ 22.86 mag in V , R and I passbands. The resulting color-magnitude V ; ( V – I ) diagram as well as their radial density profiles has been determined. Using 2MASS data, we confirmed the consistency between the 2MASS photometry, by fitting isochrones, the extinction E ( V – I ) = 0.530 ± 0.04 mag, E ( J – H ) = 0.31 ± 0.02, from the color magnitude diagram the cluster distance =2.2 ± 0.21 kpc and age = 3.6 Myr, based on the fitting of theoretical stellar isochrones of solar metallicity Z = 0.019. The distance modulus of the cluster is estimated at 12.3. The radial stellar density profiles and the cluster center have been determined by two methods. The core and cluster radii are determined from the radial stellar density profiles. Only about 40% of the cluster members are present in the core region. The cluster luminosity function has been calculated. The mass function slope of the entire cluster is ～?0.67 ± 0.12. The effects of mass segregation, most probably due to dynamical evolution, have been observed in the cluster.