500,000 stars held together, some 35,000 light years away from us, with almost 300 variable stars is known as M3 Globular Cluster. This deep sky object is probably the one which caused Charles Messier to start logging nebular objects in the sky.
Equipment: Celestron C14 + SBIG ST9XE + Astrodon I photometric filter
Exposure time: Subs of 60 seconds (so the core does not get over exposed) totaling 75 images.