| Open
Cluster
aka NGC 2422, Melotte 68, Collinder 152, Raab 55, OCL 596 RA: 07h36m36.0s Dec: -14°28'45" (Puppis) Integrated Visual Magnitude: 4.3 Angular Diameter: 29.0' Distance 1600 ly Age: 78 Myrs Minimum requirements to detect: any telescope under suburban skies |
M47 was long considered the lost Messier object, but Burnham's claimed that "the identification with NGC 2422 now seems definite" which probably went a long way toward it's general acceptance. For many, myself included, M47 is that cluster you pass over on your way to M46. Brighter and more irregular than it's neighbor M46, this is nonetheless a nice cluster. Larger telescope users may be tempted to skip M47 because it is so large and bright, but Walter Scott Houston wrote of M47 that "a coarse scattering of bright stars lies on a dim sheen of fainter ones, so a 10-inch is really needed to enjoy its splendor fully."
Burnham's points out the easy double star Struve 1121 (HD 60855) near the center of cluster. This 5.7+9.5 magnitude pair is separated by 19.6". The brighter star has a closer, 12th magnitude companion 5" distant.
I was struck by how colorless this cluster appears at the eyepiece. There are no obvious red or blue stars. Rather, all of the stars appear as a uniform, blue-gray. I also felt that M47 bears a great resemblance to M50.
The field in an 6-inch f/8
at 50x. North is down and east is to the right.
| Millennium
Star Atlas Vol I Chart 296
Sky Atlas 2000 Chart 12 Uranometria 2000 Vol II Chart 274 Herald-Bobroff Astroatlas B-06 C-40 |
