Caldwell 13, The Owl Cluster, C13, NGC457, 12th February 2020 by Webmaster The Owl cluster, not to be confused with the Owl Nebula is Caldwell object 13 and open cluster in Cassiopeia. It is a lovely object that really resembles an Owl – or I think WALLL-E or Johnny 5. Great in smallish telescopes. Images by Neil Webster