Matt's M13 - June 24, 2007
Click on the picture below for a full size image:
M13 Globular Cluster located in the constellation Hercules.
Discovered by Edmond Halley in 1714.
M13, also called the 'Great globular cluster in Hercules', is one of the most prominent and best known globulars of the Northern celestial hemisphere. It was discovered by Edmond Halley in 1714, who noted that 'it shows itself to the naked eye when the sky is serene and the Moon absent.' According to Charles Messier, who cataloged it John Bevis' "English" Celestial Atlas.
At its distance of 25,100 light years, its angular diameter of 20' corresponds to a linear 145 light years - visually, it is perhaps 13' large. It contains several 100,000 stars; Timothy Ferris in his book Galaxies
According to Kenneth Glyn Jones, M13 is peculiar in containing one young blue star, Barnard No. 29, of spectral type B2. The membership of this star was confirmed by radial velocity measurement, and is strange for such an old cluster - apparently it is a captured field star.
These are some other pictures that other Amateur Astronomers have taken (ours is better!):
http://seds.org/messier/more/m013_m2.html