John Herschel discovered NGC 2451 = h3099 on 1 Feb 1835 and recorded "The chief star (4th mag) of an orange colour, of a very large and very diffused cluster of large stars, too loose to be a fit object for the ordinary magnifying power." His position matches mag 3.6 HD 63032. Giovanni Hodierna possibly made the original discovery around 1654 though it was not included in his catalog.

NGC 2451 consists of NGC 2451A and B, two young open clusters (50-80 million years) projected on each other along the same line of sight at distances of ~600 and 1200 light years, respectively.

200/250mm - 8" (3/28/81): very bright, very large, very scattered, includes mag 4 c Puppis. Resolved in 8x50 finder.

300/350mm - 13.1" (2/25/84): very bright scattered group of stars including yellow mag 3.6 c Puppis and about 10 bright stars. This naked-eye cluster appears very large but lacking in faint stars. Recent research shows this is a random grouping and not a cluster.

Notes by Steve Gottlieb