FUZZY SPOT, February 1998, Canis Major

Canis Major is a well known constellation in the winter skies, and contains the brightest star in the sky outside of our sun.  Sirius, shining at a brightness of about -1.5 appears so bright mainly because it is so close to us, only 8.7 light years, and the 5th closest (according to Burnham, I’m sure that other very faint stars have been discovered since then).  It is only about 23 times the luminosity and 1.8 times the diameter of the sun, not a very large star.  The other claim to fame of Sirius is the white dwarf companion, Sirius B.  So far I have not been able to see the companion, but I haven’t given up yet.  If trying to find the companion, make sure you don’t want to observe anything else for a while since you definitely will loose your night vision.

Sitting in the heart of the winter Milky Way, this is open cluster country interspersed with some nebulosity.  So here are some fun objects to observe, plus a large challenging nebula complex on the Canis Major/Monoceros border.

        NGC 2204 (06h15.7 -18 39)  This is an open cluster on the far west end of the constellation.  In the 10” scope, I considered it not at all obvious with about 10-11 stars over some haze.  Star pattern around cluster forms a cross shape.  Take some time and study this one close, I will on my next observation.

        NGC 2354 (07h14.3 -25 44)  This nice open cluster is near Delta Canis Major, and is very large, not real bright, pretty loose with and estimated 40-50 stars.  There are some nice arcs in the cluster, 3 bright stars in center, and a couple of doubles.

        NGC 2359 (07h17.8 -13 13)  Here is a break from the open clusters with a nebula.  Using the UHC filter, I saw this as somewhat bright, pretty large, with the brightest portion around a grouping of 6 stars.  It extend south to another star where it abruptly ends, but turns west-southwest.  Definite mottling was seen, as was some fainter nebulosity to the north, but this is not well defined.  Some general fuzziness seen all around.  Very nice nebula well deserving of Best NGC.  Very dark to the south of nebula.

        NGC 2360 (07h17.8 -15 37)  Here is another cluster which is somewhat large, pretty bright, very rich, and somewhat condensed.  There is 1 prominent bright star, 4 levels of stars and about 90 stars with a lot of straight line groupings.  The overall shape is sort of a maple leaf pointing to the east.  To the west-northwest is a very prominent star just out of field.  Averted vision does not bring out any more stars, therefore it must be pretty well resolved.  This is a real nice cluster with some nice voids, easy to find.

        NGC 2362 (07h18.8 -24 57)  This is a very fun cluster, and one of the first objects I observed.  Here is that very first observation from my front yard, I considered it as “fairly easy to find. Tau Canis Major is right in the center.  Kind of triangular shaped.  One of the first non-major objects I have been able to find from the city.”

        For the tough object, look for the Seagull nebula on the border of Canis Major and Monoceros.  This includes nebulosity 2327 (07h04.3 -11 18), IC-2177 and Ced-90,.  Also open clusters 2335, 2343, Cr-465 and Cr-466 are involved.  The whole complex covers about 3 fields of view at 50X.  The UHC filter is really important for this area.  Ced-90 is very prominent around a bright star, elongated north/south and between 2 other stars.  Proceeding north-northwest a very faint and very very large nebulosity follows a chain of star, then turns northeast to a pair of bright stars  and clusters Cr-465 and 466.  At this point, the nebula brightens up and continues north-northwest to cluster 2335.  This is an amazing complex that I didn’t think I would be able to see.  My final notes were “really need a 35mm Panoptic, and 2” UHC filter and a hood over my head.”

Herschel 400 Objects
2204, 2354, 2360, 2362
SAC’s 110 Best of the NGC Objects
2359