It’s been said that if you’ve seen one globular cluster then you have seen them all. Certainly, at first glance, this can seem true. The Milky Way and other large galaxies have at least a few dozen of these things hanging out in the galaxy’s halo.
Upon closer inspection there are some differences. Some are more densely packed, while others have a more straggly appearance. What they all have in common is that they are, compared to other star clusters, very densely packed and the stars are very old.
M3 is one o the showcase globular clusters in the northern hemisphere. If you ask any amateur astronomer to describe a globular cluster you’ll likely get a description remarkably similar to M3 and perhaps M13.
Sadly, this is the last of my images from the observatory in West Virginia and it’s also the shortest at just 6.5 hours. It was a privilege to be able to use that facility but hopefully by the end of 2021 I will have my own observatory in my back yard.
You can find the technical details at astrobin.