Photometric analysis of some open clusters observed at the european southern observatory

In this thesis, CCD photometry of open clusters, NGC3293, NGC3766, NGC4755 and NGC6231 were detailly presented. Observations of the open clusters were taken with Danish 1.54 metre telescope on 3th of March 2013 and between 8th and 25th March 2014. After member stars of each cluster were identified from the proper motions of the stars in the field of view of open clusters, structural and astrophysical parameters were obtained from the photometric data in UBV filters. For the open clusters, the colour excesses determined using two-colour diagrams were found as 0.29±0.05, 0.20±0.03, 0.34±0.03 and 0.45±0.05 mag, respectively, and the distances to the clusters were calculated as 2586±240, 2159±215, 2136±175 and 1679±143 pc from Gaia parallaxes. It was assumed that metallicities of the clusters are as Solar metallicity (Z=0.0152) since they are too young to estimate photometric metallicity. Furthermore, using these parameters, ages of the open clusters were also calculated from CMD using PARSEC theoretical models are 10±6 Myr, 14±6 Myr, 22±6 Myr and 4+6-3 Myr, respectively. Additionally, slopes of initial mass function for the open clusters range between 1.14 and 1.25 which are comparable to the value 1.35 for the Solar neighbourhood.