The biggest and brightest Globular Cluster easily visable from the USA.
M13 was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764.

It is located at right ascension 16h 41.7m and declination +36° 28'. With an apparent magnitude of 5.8, 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. Nearby is NGC 6207, a 12th magnitude edge-on galaxy that lies 28 arc minutes directly north east. A small galaxy, IC 4617, lies halfway between NGC 6207 and M13, north-northeast of the large globular cluster's center

This is one of the best objects in the Northern skys. It can be seen with binoculars. An 8" to 12" scope would be needed to see what this photo shows.


Taken on the first moonless clear night since early January. Right at 1.5 hours of exposure. 30 minutes each of red, green and blue through colored filters.

Location: west of Columbia, MO

Telescope: William Optics FLT110 @f7 no flattener (photoshop flattened)

Camera: SBIG ST-8300 w/5 position filter wheel and Baader color filters

5 x 360 seconds for Red, Blue and Green filters
Guided with PHD Guide and an Orion Starshoot guider

AP Mach1 GTO mount (this is a great mount - way better than my Celestron CGE that I used for years.)

Processed with CCDStack and PixInsight LE & Photoshop CS5