M25 -- Open Cluster in Sagittarius
“A Pretty Knot of Minute Glimmers”
I have always found it interesting that M25 was never given an NGC number. This open
cluster is easily visible to the unaided eye when one is under pristine skies. Through the
telescope it is an eye-catching array of arcs formed by the brightest stars subtly
embedded within the nebulosity of hundreds-of-stars too dim to be made out individually
through the telescope. At the center of the cluster is what Admiral Smyth called “A Pretty
Knot of Minute Glimmers”. It could not have been described better.