Star Clusters:

Studies of individual stars and star-clusters in nearby galaxies mainly with the Hubble Space Telescope give us a picture of their history. Based on these data we can decipher when the stars in each area of a galaxy were formed, which in turn gives us information on the processes that shaped the present picture of a galaxy. In addition we can obtain important information on the mechanisms of star-formation and the factors which affect them. This information is also important for understanding their populations of X-ray binaries and supernova remnants.