Hercules globular cluster
The Hercules globular cluster was discovered in 1714 par E. Halley. It is one of the finest globular clusters. It contains several hundreds of thousands of stars and its apparent diameter is about half that of a Full Moon.
It can be seen with the naked eye as a small blurred spot, but requires a telescope of diameter at least 15 cm to reveal the stars around it.
This cluster was chosen in 1974 as the destination of one of the first radio messages to any possible extraterrestrials.
Photographed by "Chamois" (the person's pseudonym on the Futura-Sciences astro forum) with an exposure time of 1 hour 10 min. a CCD camera and a 200mm diameter telescope.
Hercules globular cluster - 1 Photo