Globular Cluster M3

M3 is a rich globular cluster of about 500,000 stars including a large number of variables. It was Charles Messier's first orginal discovery (1764). William Herschel first resolved M3 into stars, defining it as a cluster around 1784. M3 appears small but quite impressive visually. It is partially resolved in my 4" telescope even under bright skies.

Globular Cluster M3
(Click image to enlarge)

Object Details:

Type: Globular star cluster
Constellation: Canes Venatici
Distance: 33,900 light-years
Diameter: About 180 light-years

Upper Image Details:

Date: Mar. 25, 2012
Site: Harahan, LA
Exposure: CCD, 15 x 4 min.
Filters:  IDAS LPS-V4 48mm
Processing: MSB Astroart 5.0
Telescope:  8" Celestron EdgeHD
Reducer:  None (f/10)
Image CCD: SX SXV-H9C
Guide CCD: SX MX7C
Guide Scope: Vixen ED80Sf

Lower Image Details:

Scale: 571 x 426 light years
Date:  March 18, 2007
Site: Harahan, LA
Conditions: Clear, Dew
Exposure: CCD, 25 x 4 min.
Filters:  IDAS LPS-P48
Processing: MSB Astroart 3.0
Telescope: 4" Tak FSQ-106N
Reducer:  None (f/5.0)
Image CCD: SX SXV-H9C
Guide CCD:  SX  MX7C/SXV Int.
Guide Scope: Vixen ED80Sf

For more on globular clusters, see my M13 (Hercules) Globular Cluster page.