Messier 3, a globular cluster

Messier 3 is a large globular cluster near the constellation Bootes. It is documented to be the first object in Messier's catalogue discovered by Charles Messier himself in 1764. It took another two decades until William Herschel finally could resolve individual stars and correctly classified its nature.

With about 500.000 stars it not only is one of the largest globular clusters in the northern sky, it also is one of the best studied clusters.

M3 is bright enough to be observed visually with smaller telescopes, even if it only presents itself as a smudge spot between stars.

In order to resolve the inner stars a longer focal length and larger aperture is required: This image was taken with a 10 inch Newton telescope, which probably is the minimum requirement for this.

And even with a focal length of 950mm, the image still is a crop from the full APS-C field: