Globular cluster M5 was cataloged by Charles Messier in 1764, 62 years after it was discovered by Gottfried Kirch. It is one of the oldest globular clusters associated with the Milky Way, with an estimated age of 13 billion years.
M5 is about 24,000 light years from earth, and has a diameter of about 165 light years. It contains roughly 100,000 stars, many of which are red giants. Like all globular clusters, M5 does not belong to our galaxy, but orbits it, caught in the gravitational field. Its position as seen from Earth puts it in the constellation Serpens.
The bright star below M5 in this photo is 5 Serpens, and it is actually too faint to be seen with the unaided eye in typical suburban skies. 5 Serpens is a binary star system, containing two stars separated by about 11 arc-seconds. If you view this photo in its "original" size (click the "original" link below), you can make out the smaller companion star at about the 10 o'clock position, very close to the main star.
This image is a combination of 30 photos taken on the night of 19-Jun-2008, with an 8" f/5 newtonian reflector telescope and a Canon Digital Rebel XT. The 30 exposures were made for 90 seconds each at ISO 400 and guided with a Meade DSI-C CCD camera attached to an 80mm f/11.2 refractor. The images were processed with Iris software and final adjustments were made in Photoshop.