"NGC 2359 is an emission nebula in the constellation Canis Major. The nebula is approximately 3,670 parsecs (11.96 thousand light years) away and 30 light-years in size. The central star is the Wolf-Rayet star WR7, an extremely hot star thought to be in a brief pre-supernova stage of evolution. It is similar in nature to the Bubble Nebula, but 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."
The nebula contains several hundred solar masses of ionized material, plus several thousand more of unionized gas. It is largely interstellar material swept up by winds from the central star, although some material does appear to be enriched with the products of fusion and is likely to come directly from the star.[5] The expansion rate of different portions of the nebula varies from 10 km/s to at least 30 km/s, leading to age estimates of 78,500 - 236,000 years." https://en.wikipedia.org/wiki/NGC_2359

"WR 7 (HD 56925) is a Wolf–Rayet star in the constellation of Canis Major. It lies at the centre of a complex bubble of gas which is shocked and partially ionized by the star's radiation and winds.
The distance is uncertain, with estimates between 3.5 kiloparsecs (11,410 light-years) and 6.9 kiloparsecs (22,500 light-years). Assuming a distance of 4.8 kiloparsecs (15,600 light-years), this star is calculated to be 229,000 times brighter than our Sun, 13 times more massive, and 1.26 times larger with a surface temperature of 112,200 K. This makes it currently the second smallest known WN star in the galaxy, after WR 2.
Stars of its kind are characterized by a rapid loss of stellar mass, driven by chemically enriched high-speed stellar winds. It is estimated that it loses mass at the rate of 7x10−5 solar masses each year through winds of 1,545 km/s."
NGC 2359 is excited by the ionizing radiation of WR7... is approximately 4pc across and prominent at wavelengths from radio to X-ray" .https://en.wikipedia.org/wiki/WR_7

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This is a nebula that captivated us since we saw the first images. Since we cannot capture it from our backyard, when Maurizio had the opportunity to do sessions, he took advantage of those mountain sites that also offer excellent seeing.

This project has data acquired in Dec 2021 and January 2022. I was hesitating whether to process it because there were only three sessions and one of them was very short, but curiosity was great and I did it.

A first stack was made in normal AHD DSS and after processing it quickly I opted to make a stack in 2 drizzle. Then I did the same with Siril (normal and 2 drizzle) and the extraction of Ha and [OIII].

I learned in DSS how to make the complete stack with both filters and their respective calibrated frames and thus obtain a final result with everything in a single pass. So at least I save a step less in the future.

Four stacks plus Ha and [OIII] were processed. Workflow was applied on starless images using Star eXterminator on normal stacks and StarNet on 2 drizzle stacks.

The stars were taken from the initial DSS stack as the end result offered pretty, naturally colored stars.

In the workflow, 2 initial Arcsinh 10 curves were applied, the gradient was extracted (very little actually), in CamRaw: Clarity, Dehaze, White, Shadow and Texture. Then Noise eXterminator and Denoise AI were applied. In one of the stacks I don't remember which one I had to apply an additional denoise. Smart sharp as a final touch.

The coloration of this nebula is practically natural, it is incredibly beautiful, only a little saturation was used in the blue, cyan, orange and red.

For the first time I used the information from the OIII as the main luminance, it is impressive how strong it is in the nebula and the Ha as a buster of the other parts of the image that were dimmer.

A final ensemble was then made with the results of all the processes, giving different percentages to each one on the layers.

We are quite satisfied with the final result for the first time we have developed it. We hope to be able to add more data to it in the future since the region around the Nebula is immersed in a very rich HII region and it would be interesting to have another version with that additional information.

Thank you for visiting us and seeing our work, we hope you like it.

Processed July 2022