M5

Despite the round appearance of the image below, M5 shows a distinct ellipticity and is thought to be one of the oldest globular clusters, with a computed age of 13 billion years. Its diameter is about 165 light years, making it one of the larger globular clusters and at its distance of 24,500 light years, this diameter is about 23 minutes of arc, although visually it appears somewhat smaller, about 10 or 12 arc minutes. It has a compressed central core of roughly 6 light years diameter. M5 contains the considerably large number of 105 known variable stars. Under very good viewing conditions, M5 can just be glimpsed with the naked eye. A telescope with a 4-inch objective can begin to resolve its brightest stars. Larger telescopes or photographs reveal a spectacular sight with thousands of stars and the halo extending to over 15' diameter. M5 lies near to the bright double star 5 Serpentis, the faint and distant globular cluster Palomar 5, and a collection of faint and distant galaxies.

Taken June 20, 2012, with the C-14 operating at F:3.5 and the ST-8 camera binned 2 X 2. Exposure is 400 seconds.