Great Hercules Cluster
Updated: Aug 4, 2025
#Messier13, #NGC6205, and #PMC39
About this object
Messier 13 (M13/NGC 6205), the legendary "Great Hercules Cluster", reigns as the northern sky’s brightest globular cluster, a dazzling sphere of 300,000 ancient stars packed into a 145-light-year-wide orb over 22,200 light-years from Earth. This 11.65-billion-year-old stellar metropolis (metal-poor at [Fe/H] ≈ -1.35) shines at magnitude +5.8, its core so densely packed that stars are only 0.04 light-years apart—near-collision distances that fuel exotic blue stragglers and millisecond pulsars. M13’s gravitational might (total mass: 600,000 suns) makes it a prime target for studying dynamical evolution in globulars. Its position in Hercules’ "Keystone" asterism and spectacular 1974 Arecibo radio message destination cement its status as a crown jewel of deep-sky observing.
Designations
Standardized Catalogues
PMC Observatory Catalogue
Observations
2025-08-02 at around 10:30 pm +01:00
Photographs
