Optical CCD image of the globular cluster M13 (NGC 6205) in the constellation of Hercules. M13, discovered in 1714 by Edmond Halley, is the finest and largest globular cluster in the northern hemisphere. The cluster is at a distance of about 22,500 light years and contains roughly half a million stars. Over a hundred globular clusters are known in our galaxy and they are distributed throughout a sphere, the halo, which surrounds the whole galaxy. Globular clusters are usually populated by faint and old stars such as white dwarfs and red giants. The image was obtained with blue-green, red and near infrared filters and it may be considered a true colour version.