NGC 2359 (also known as Thor's Helmet) is an emission nebula in the constellation Canis Major. The nebula is approximately 15,000 light-years away and 30 light years in size. Known as a Wolf-Rayet star, the central star is an extremely hot giant thought to be in a brief, pre-supernova stage of evolution.
It is similar in nature to the Bubble Nebula, interactions with a nearby large molecular cloud are thought to have contributed to the more complex shape and curved bow-shock structure of Thor's Helmet.  [Source Wikipedia].

IMAGE information -- 2022
This is a combination of OIII and R, G and B.
OIII : 43 subs (3.58 hrs.) on Mar 9th and 12th.
RED : 21 subs (1.75 hrs.) on Mar 9th and 12th.
GRN : 20 subs (1.66 hrs.) on Feb 27th and Mar 9th.
BLU : 20 subs (1.66 hrs.) on Feb 27th and Mar 9th.

All exposures were at 5 minutes (300s) each, 1x1 bin, -10C, Gain 1600 and Offset 56.

Color was created using the Red, Green and Blue filters.  These images were individually integrated and then combined into a color image.  Luminance was generated using only subs from the OIII filter.  This was then fully processed and combined with the RGB image for full definition.
Processing was done with PixInsight, following (for the most part) kayronjm's tutorial of Feb. 24th from several years back.

COMMENTS:
This is the forth effort with this target. The first was in 2011 with the Canon 450D XSi (modified) DSLR.  The second in 2011 and the third in 2021, with the Atik 383L+mono CCD.  This last one is with the new QHY294mm Pro mono CMOS camera.

I continue to image with my new QHY294m Pro mono cmos camera, and settled on the “gain” and “offset”  settings (1600 and 56 respectively), and the use of Lights, Darks, Flats and Flat Darks for processing.

I had expected to use (as per usual) the images from the Ha filter for the luminance to combine with the RGB.  However, I found I liked the resulting image from the OIII filter better.

This target is relatively low in the south and required I get back up in the trees and “prune” my oak that stands immediately to the