Abstract
We present deep CCD photometry (V similar to 2 1 mag) in BVRI Johnson-Cousin filters supported with 2MASS JHK data set for the old open star cluster NGC 2266. The cluster's parameters such as reddening, distance, metallicity and age, etc ..., are derived using two color diagrams in optical and near-infrared bands. These parameters are EB-V = 0.196 +/- 0.02, EJ-H = 0.068 +/- 0.001 and EJ-Ks = 0.163 +/- 0.01 mag, the distance modulus of (m - M)(0) = 12.08 +/- 0.11 mag, which gives a distance of 2.6 +/- 0.15 kpc, the metallicity, Z = 0.004, and age of 1 Gyr (obtained by fitting the observed CMDs with Padova isochrones). The limiting radius of the cluster is obtained of 7.03 +/- 0.27 arc minutes from the analysis of 2MASS data; it reflects that the cluster is a compact cluster. Luminosity and mass functions are investigated as well as the dynamical relaxation time of NGC 2266 is determined of about 0.02 of its age, which means that the cluster is dynamically relaxed.