Messier 13, also known as the Great Hercules Cluster, is one of the finest globular clusters visible from the Northern Hemisphere. Located approximately 22,000 light-years away in the constellation Hercules, this vast stellar swarm contains several hundred thousand stars packed into a region about 145 light-years across. Many of its stars are ancient, dating back over 11 billion years.

This deep LRGB image was captured over 17 hours and 50 minutes, revealing the dense, bright core and intricate halo of stars that extend outward into the surrounding field. Blue-tinged horizontal branch stars and cooler red giants are easily visible. The Great Cluster continues to be a popular target for both visual observation and astrophotography, showcasing the grandeur of stellar evolution in our galaxy’s halo.

Messier 13, or the Great Hercules Cluster, is a massive globular cluster located about 22,200 light-years from Earth in the constellation Hercules. This densely packed sphere of stars spans roughly 145 light-years in diameter and contains several hundred thousand ancient stars. Its brilliance and size make it a favorite target for both amateur and professional astronomers in the northern hemisphere.

With an age of approximately 11.65 billion years, M13 is among the oldest known structures in the Milky Way. Its core shines with densely concentrated stars, while its outskirts appear gradually more diffuse. This detailed image captures the varied star colors—ranging from cooler orange giants to hotter blue stars—emphasizing the cluster’s aged and evolved population.

Messier 13, a globular cluster of hundreds of thousands of stars, in the constellation Hercules. It is around 24,000 light years from earth, and approximately 145 light years in diameter.
Imaged during a full moon.
Astrodon Blue: 12x300"
Astrodon Green: 15x300"
Astrodon Red: 15x300"
Astrodon Luminance: 71x300"
Total Integration: 9.4 hours
Captured on my dual rig in Spain.
Scopes: APM TMB LZOS 152 (6" aperture 1200mm focal length)

Copyright: Peter Goodhew