NGC 2359 is an emission nebula tucked away in the northeast corner of Canis Major. You'll find it 4.3 degrees northeast of 4.1 magnitude Gamma (23) Canis Majoris. My drawing is based on an 82X view in the 10-inch Starfinder. It shows NGC 2359 as a 12' by 9' curved nebulous patch shaped like a stubby boomerang. Larger aperture reveals more detail, which has earned this nebula the moniker, Thor's Helmet. A nice grouping of 10th to 12th magnitude stars lies immediately to the east and several 13th magnitude and fainter stars are superimposed on the nebula. While in the area, seek out the fine Messier cluster, M47, 4.6 degrees to the east-southeast.

In the big Dob, NGC 2359 really comes to life. A UHC filter really gets the show going. The iconic "helmet" is clearly visible at the center of my drawing. The sketch presents a 109X view in the 18-inch. The most prominent feature of the helmet is a bright arc of nebulosity curling west of a star near the center of the drawing. At the southern tip of this arc, a tapering 8' by 2' finger points to the southwest. A string of four faint stars parallels this finger along its northern edge. A large, faintly glowing cloud covers much of the field west and south of the helmet. More subtle patches of ionized gas are seen just inside the southeast border and to the northeast of the helmet. A very delicate foggy patch surrounds 10.7 magnitude Tycho 5403:778:1. Another gauzy haze lies between 11.3 magnitude Tycho 5403:754:1 and 12th magnitude GSC 5403:2038. More than 80 stars are scattered throughout the field of view.