M22

Alt. Designations: NGC 6656
Object Type: Globular  Cluster
Constellation: Sagittarius
Distance: 10.4 kly
Right Ascension: 18h 36m 24.2s
Declination: -23° 54´ 10"
Visual Magnitude: 5.1
Apparent Dimension: 32.0´ Dia.
Best Month To View: Jun

M22 is one of the nearer globular clusters to Earth at a distance of about 10,600 light-years away. It spans 32' on the sky which translates to a spatial diameter of 99 9 light-years. 32 variable stars have been recorded in M22. It is projected in front of the galactic bulge and is therefore useful for its microlensing effect on the background stars in the bulge. Despite its relative proximity to us, this metal-poor cluster's light is limited by dust extinction, giving it an apparent magnitude of 5.5 making it the brightest globular cluster visible from mid-northern latitudes . However, due to its southerly declination, M22 never rises high in the sky and so appears less impressive than other summer sky globulars such as M13 and M5.