Hercules Globular Cluster
" M 13 "

IMAGE DETAILS

Object ............................................ Hercules Great Globular Cluster
Constellation ..............................   Hercules
RA / DEC ..................................... 16h:41m.41sec / +36 27m.35sec
Distance + Ap. Magnitude.........  25.100  Light years  /  5.8
Date + Time ...............................   18/06/2013 - 17:20 UTC
Location ....................................   
"Nunki Observatory" - Skiathos
Optics .........................................    
Celestron C11 HD f/10
Tools ..........................................   
CCDsoft
Camera .....................................  
SBIG ST10XE  with CFW10 (Astrodon filters)
Exposure Time.......................     Luminance: 11 X 30 sec , RGB : 5 X 300 sec (each)
More Details ...........................    Environment Temperature : 23oC Camera Temperature 20οC
Mount .......................................   Paramount ME
Guiding ....................................   Unguided
Processing Details ................    Photoshop , CCDsoft
Notes ........................................   Weather: Partialy thin clouds  Transparence: Mediun Humidity : 65%

Target details .........................  
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 was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764.
It is barely visible with the naked eye on a very clear night. Its diameter is about 23 arc minutes and it is readily viewable in small telescopes.

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 human race, DNA, atomic numbers, Earth position, was beamed there for being picked up by a potential extraterrestrial civilization. It will reach the cluster in 25,100 years.
 

Nikos Paschalis