Object Analysis

Messier 5 (M5) is a globular cluster in the constellation Serpens. Discovered by Gottfried Kirch in 1702, it is one of the oldest globular clusters associated with the Milky Way, estimated to be 13 billion years old. It spans 165 light-years in diameter.

M5 is elliptical in shape and is thought to be one of the larger globular clusters, containing anywhere from 100,000 to 500,000 stars. It is located 24,500 light-years from Earth. It contains a significant number of variable stars—105 RR Lyrae variables have been identified, which are used to measure distances in the universe.

Under good conditions, M5 is visible to the naked eye as a faint "star" near the star 5 Serpentis. Binoculars reveal its non-stellar nature, and larger telescopes resolve thousands of stars into a glittering ball of light.