|Object Type||Open Cluster|
|Size||20.0' x 20.0'|
Situated about 15 degrees east of the bright star Sirius is a pair of bright open clusters, M46, and M47, both of which are easily visible to the naked eye. The two clusters are visible together in binoculars and make an interesting contrast to each other. In the photograph above, M47 is partly visible near the top of the image, a little right of centre.
A more detailed look at M47 is here.
The entire region is rich with stars and star clusters. In the photograph above, M46 is close to the centre, with M47 to the right. Above M47 is the open cluster NGC 2423. Towards the top right is the cluster CR 155. In total there are 9 open clusters visible in the photograph.
45 minutes exposure, Fuji Super HG II 400 film.
5" f/5 refractor at prime focus.
M46 is a large, rich cluster of moderately bright stars, that is a fine object in the telescope. The stars tend to be fairly uniform in brightness and the cluster is almost circular in shape. Of particular interest is the small planetary nebula, NGC 2438, visible near the northern (top) edge of the cluster. Although the planetary appears to be part of the cluster, it is in fact a foreground object, being only about half the distance as M46. The planetary is easily visible in an 8" telescope at moderate magnification as a distinct ring. The combination makes for a good way of seeing depth in the sky. They are also very good for showing to non-astronomers. Given that the planetary is a couple of thousand times larger than the solar system, it makes the background cluster seem huge. In the photographs above, which roughly correspond with a binocular view, the planetary is just visible as a small orange "star" near the top centre of the cluster.
45 minutes exposure, Fuji Provia 400 film.
300mm f/6 newtonian at prime focus.