Messier 13 (M13), also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of about 300,000 stars in the constellation of Hercules.

M13 is about 145 light-years in diameter, and it is composed of several hundred thousand stars, the brightest of which is the variable star V11 with an apparent magnitude of 11.95. M13 is 25,100 light-years away from Earth.
The Arecibo message of 1974, containing encoded information about the human race, DNA, atomic numbers, Earth’s position, and other information, was beamed towards M13 to allow it to be picked up by potential extraterrestrial civilizations in the cluster. The message will reach the cluster in 25,000 years.

Imaging telescopes or lenses: Meade Model 2080
Imaging cameras: Canon 600D
Mounts: Sky-Watcher HEQ5 PRO
Guiding telescopes or lenses: Celestron 80mm Guidescope
Guiding cameras: Sky-Watcher Synguider
Focal reducers: Meade f/6.3
Software: PixInsight, BinaryRivers BackyardEOS
Dates: Aug. 25, 2013
Locations: Roof terrace, Borås, Sweden
Frames:
10×120″ ISO800
10×180″ ISO800
12×60″ ISO800
Integration: 1.0 hours
Darks: ~10
Flats: ~16
Bias: ~20

Author: Peter Folkesson

AstroPhotography of the day by SPONLI
19 May 2014