M4 - Globular Cluster in Scorpius
M4 is a globular cluster - a dense, gravitationally-bound collection of stars. Globular clusters orbit the galaxy, forming a halo outside of the main body of the galaxy. They are found in almost every galaxy. M4 contains tens of thousands of stars in an area about 75 light years across, 7,000 light years from Earth. It is less densely packed than many globulars so many stars are resolved even in relatively small telescopes. At magnitude 5.9, it is difficult to see with the naked eye but is easily visible in binoculars and small telescopes as a fuzzy patch the size of the full Moon.
5 minute exposures: 3 each R, G, B, and 5 luminosity
SBIG ST-8300M cooled CCD camera
Orion 8" F/3.9 Newtonian with Baader coma corrector
Shot and processed with Nebulosity
Taken June 19, 2017, Santa Cruz Mountains, California
