The Head of Canis Major
By Shawn Grant
February skies are one of the most beautiful skies of the year. The diversity of deep sky objects is so vast. There are many galaxies, nebula, open clusters and dark nebula. Many nights the skies are crystal clear and the Milky Way is a beautiful stream of stars that flow through Orion, Monoceros, Puppis and Canis Major. As one gazes at this complex of beauty they will usually spot a very bright star. This star is Sirius which some say makes the diamond in Canis Major, Orion's big dog's collar. There are two 4th magnitude stars to the east of Sirius Gamma CMa (fl 23) and Theta CMa (fl 14) that makes the head of the dog. We are going to tour the open clusters and nebula east of this head. This region receives little attention but it has many mind-blowing objects in it. So lets start exploring.
Point your telescope to Gamma CMa. This star will be used as a reference and a starting point of this star hop. The first object we are going to observe is Haffner 4. It is located 40 minutes northeast of g. This is a small open cluster with a size of 2.4 minutes and it is faint with the brightest star being 14th magnitude. This cluster will require a 12 inch or larger to view. If you have this large of a scope which many of us do use fairly high power to resolve the cluster. The cluster probably has about 30 members. It is fairly rich and compact. A nice cluster and a challenge as well.
µ cma. is a nice double star located between Gamma and Theta cma. The first star is 5.1 magnitude and the second is 8.1. They are separated by 2.8 seconds with a position angle of 342. This is a very pretty pair of yellow and blue stars. The double is very nice colorful eye candy.
Just a degree to the northeast of µ cma. is the open cluster NGC 2318. NGC 2318 is not very well known or observed much. I tried to observe the cluster on one occasion and I could not see any sign of a cluster of stars at the specified location. The cluster is not listed in the observer's guide. Dreyer describes the cluster as large, scattered stars of a magnitude ranging from 8 to 9. There are a few stars in that area that are bright but not of a concentration of a cluster. Take a look at this cluster and see if you can determine if there is some detachment from the rest of the background.
30 minutes to the east of NGC 2318 is the open cluster Ruprecht 8. It has a size of 4 minutes and the brightest star is 12th magnitude. The cluster is sparse and hard to pick out from the background. I noticed that the cluster has a triangle shape to it. One of the neat things about observing this cluster is that most people have not.
Move a degree northwest to the open cluster Ruprecht 7. This cluster is a little better then the last two. It is 4 minutes in size and the brightest star is 14th magnitude so you will need a large scope to view the cluster. The cluster is detached with some compression of a dozen or so stars. I noted that there was some background haze due to unresolved stars.
Ruprecht 7 has a little neighbor just 24 minutes to the west called Ruprecht 6. It is very small with a size of 2 minutes. I could not find a magnitude listing for the cluster but it will require a large telescope to spot. When I observed the cluster I could only detect a very faint haze with averted vision.
Three degrees to the east we come to a much better cluster NGC 2345. It is 12 minutes in size and
has a magnitude of 7.7. The cluster is well detached and nice to look at. The cluster has a few brighter 8th to 10th magnitude members that display some color. The overall shape of the cluster is an arrowhead. It is one of the clusters you will remember long after you finish observing it.
Now it is time to break out your nebula filter. vdB 94 also known as Ced 90 is a nebula located just 1 degree northwest of NGC 2345. It has a size of 10 X 10 minutes. This nebula is brighter and lower portion of a large nebula complex that includes NGC 2327 and IC 2177. The nebula is fairly faint with the western portion brighter then the rest. The nebula for the most part is featureless. This would make a good photographic or CCD object.
Move a little to the north to the main nebula complex of NGC 2327, IC 2177, Ced 87d, vdB 93. This is a huge complex that stretches 2 degrees north and south into Monoceros and 1 degree east and west. On very dark nights this complex can be glimpsed with 50 mm binoculars. In the telescope use an 0III or a UHC filter and a wide angle eyepiece to best view the nebula. The nebula looks like a faint cirrus cloud with the brightest portion to the north. Spend several minutes observing the nebula. It is very complex and requires time to fully observe and appreciate.
About 30 minutes east of the nebula complex is the open cluster Berkeley 76. Berkeley 76 is a tough cluster to spot. It is sparse and only has a few stars. It isn't detached at all. In fact it looks like the rest of the area. I am not sure why this was considered a cluster, but that is what makes it fun. Try to determine if you can detect any compression or even a hint of a cluster.
A little over 3 degrees to the southeast of Berkeley 76 is the Duck Nebula NGC 2359 with IC 
468 involved. This is a fairly nice nebula that is rarelyobserved but is photographed often. A nebula filter such as the UHC, ultrablock or OIII really brings this nebula out. In the south there is a prominent streak that flows to the east and west. The northern region reveals various filamentary structures. Spend a lot of time on this nebula it is very complex in detail. This is truly a wonder in the sky. It amazes me why this object is not observed much.
22 minutes to the east of the Duck Nebula is the open cluster Haffner 6. It is 4 minutes in size and is detached. The cluster is very faint but looks nice in a large telescope. It is a scattering on very faint stars 14th magnitude or fainter. The cluster has a hazy background of unresolved stars.
Our last object on the tour is Basel 11A. It is located 48 minutes southwest of the Duck Nebula. It is in a pretty section in the sky. It is between an 8th and a 9th magnitude stars. There are about a dozen loosely scattered stars from 11th to 14th magnitude. It is well detached from the background. It is a lovely jewel in the sky.
There are a few objects that were left out of the tour that are worthy of observation. This is an area that you can spend a whole winter exploring its wonders. Go out and explore.