M3 on 03-12-2008

Done with my 17.5 inch scope and SBIG ST-9E CCD camera

Globular Cluster M3 (NGC 5272), class VI, in Canes Venaciti 

M3 is one of the most outstanding globular clusters, containing an estimated half million stars! It is extremely rich in variable stars: According to B. Madore (in Hanes/Madore, Globular Clusters, 1978), 212 variables have been found, 186 periods determined, more than in every other globular cluster in our Milky Way galaxy (and thus the most ever observed); at least 170 RR Lyrae variables were discovered. 

This cluster was the first `original' discovery by Charles Messier when he logged it on May 3rd, 1764. At that time it was the 67th deep sky object ever observed by human eyes.  It was apparently the discovery of this object which eventually caused Charles Messier to start a systematical search for these comet resembling objects.


Right Ascension 13 : 42.2 (hours : minutes)
Declination +28 : 23 (degrees : minutes)
Distance 30,600  light-years
Visual Magnitude 6.3 
Apparent Dimension 16.2 (arc minutes)

OBJECT = M3
TELESCOPE = 17.5 inch f3.23
CAMERA = ST-7E 
OBSERVER = Rusty Fletcher 
 LOCATION = Seguin Outdoor Learning Center 
DATE (Yr-Mo-Dy) = 2004-12-15
TIME (UT) = 11:49:25
IMAGES STACKED = 8
INDIVIDUAL EXPOSURES = 50 sec.
TOTAL EXPOSURE TIME = 400 sec.
                                                                           

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