M13 a globular cluster in the constellation Hercules. M13 is sometimes called the Great Globular in Hercules, as it is one of the most noticeable globular clusters in the northern hemisphere. About 22000 light-years away and about 150 light-years across, M13 contains perhaps as many as a million stars. It is slightly closer and a little older than its near neighbor M92. This moderately shallow color picture was made from CCD images taken at the Burrell Schmidt telescope of the Warner and Swasey Observatory of the Case Western Reserve University, located on Kitt Peak in southwestern Arizona. The contributing images were taken during the Research Experiences for Undergraduates (REU) program operated at the Kitt Peak National Observatory and supported by the National Science Foundation.