Globular Cluster M5 (NGC 5904), class V, in Serpens

Right Ascension 15 : 18.6 (h:m); Declination +02 : 05 (deg:m) ; Distance 24.5 (kly) ; Visual Brightness 5.6 (mag) ; Apparent Dimension 17.4 (arc min)

M5 shows a distinct ellipticity, elongated at position angle 50 degrees (position angles give the orientation of a feature in the celestial sphere; they are measured between North and the direction considered, in counterclockwise sense); it is thought to be one of the oldest globular clusters, with a computed age of 13 billion years. Its diameter is about 125 light years, making it one of the larger globular clusters. At its distance of 24,500 light years, this diameter is about 17 minutes of arc. M5 is receding from us at about 50 km/sec.

Source and more: SEDS

May 3, 2003 22:32 - 22:42 UT
Focal Reducer, 8 x 20 seconds exposure.