Messier 3
Object type: globular cluster
Size: diameter ~ 18'
Visual Brightness:~ 6.2
Constellation: Canes Venatici
Exposure data
Date: 2007-04-22
Location: Postalm/ Austria (1300m)
Telescope: TMB 80/480 (3.1" Apo f=480mm)
Camera: Starlight XPress SXV-H9
Astronomik Infrared block filter
Image type: LRGB
Exposure time total: 2h 50'
L: 40 x 2' = 80'
RGB: 90'
Discovered 1764 by Charles Messier.
Messier 3 is one of the most outstanding globular clusters, containing an estimated half million stars. It is famous for the large number of variable stars discovered in it. This cluster was the first 'original' discovery by Charles Messier when he logged it on May 3rd, 1764. M3 was first resolved into stars and recognized as cluster by William Herschel around 1784. Globular cluster M3 is extremely rich in variable stars.M3 contains a relatively large number of so-called Blue Stragglers, blue main-sequence stars which appear to be rather young, much younger than the rest of the globular's stellar population would suggest.