Globular Cluster M4
M4, Messier 4, NGC 6121
M4 is roughly 5,600 light-years (1,720 parsecs) from the Earth.
Data for this release was taken from HST proposals 5461 and 8679 together with archived observations from HST proposal 8153. The full team involved in this discovery is composed of Brad Hansen (UCLA), Harvey Richer (UBC), Steinn Sigurdsson (Penn State), Ingrid Stairs (UBC) and Stephen Thorsett (UCSC).
F336W (B) 11,800 sec, F555W (V) 15,000 sec, and F814W (I) 4800 sec
NASA and H. Richer (University of British Columbia)