M56

About

A globular cluster in Lyra, about 32,900 light-years away, roughly midway between Albireo and Sulafat. It follows a retrograde orbit, which suggests it came from a merged dwarf galaxy. It is very metal-poor, with about 1/100 of the Sun's heavy-element content.

Imaging tips

• Only about 7–9′ across: 3,460–5,770 mm on APS-C, and too small to frame on full frame, so use a long focal length.
• Easy to photograph even from a Bortle 9 backyard: one hour of 30 s subs with no filter still resolved many individual stars.
• Another image, 80 minutes of RGB in 10-minute subs on a 130 mm refractor, was taken from Alberta; its author notes the cluster gets less attention than M57 next door.
• Best in June and July, high in the sky from northern latitudes.