NGC 2451 is listed as an open cluster in the constellation of Puppis but is actually two open clusters lying within the same line of sight.
It is set within a region that has hydrogen alpha emissions in the background from the Gum Nebula.
To the lower left is NGC 2477 a dense open cluster.
Imaged in LRGB and Hydrogen Alpha on my Planewave DR 350 at Observatorio El Sauce, Chile.
Image acquisition and processing: Mike Selby