Messier 93 or M93, also known as NGC 2447 or the Critter Cluster, is an open cluster in the modestly southern constellation Puppis, the imagined poop deck of the legendary Argo.

It was discovered by Charles Messier then added to his catalogue of comet-like objects in 1781.

[7] Walter Scott Houston (died 1993) described its appearance:[8] Some observers mention the cluster as having the shape of a starfish.

With a fair-sized telescope, this is its appearance on a dull night, but [a four-inch refractor] shows it as a typical star-studded galactic cluster.It has a Trumpler class of I 3 r, indicating it is strongly concentrated (I) with a large range in brightness (3) and is rich in stars (r).

[11] Four spectroscopic binary systems within include a yellow straggler component.