Thor's Helmet (NGC 2359) - Emission Nebula in Canis Major - Astrophotography
Updated: May 18, 2023
NGC 2359 is a cloud of interstellar gas that resembles Thor’s Helmet. Although very faint, the colors in the gases really pop when taking long exposures, with both an astrophotography dedicated camera and a DSLR.
This beautiful deep-sky object gets its glow from WR7, a massive Wolf-Rayet star that will soon turn into a supernova.
We recommend as many hours as your patience can allow to capture this target. While a total of 4 hours can yield fair results, additional time will give you all the faint gases surrounding NGC 2359. Those are not often seen in amateur photographs but make for a really impressive final image.
Make sure to watch Episode 15 of Galactic Hunter to see how we imaged Thor's Helmet!
Object Designation: NCG 2359
Also known as: Thor's Helmet Nebula
Constellation: Canis Major
Object Type: Emission Nebula
Distance: 11,970 light-years away
Magnitude: 11.45
Discovered in: 1795
Thor's Helmet Nebula has a truly unique shape! It obviously got its name from the shape of the helmet of the Marvel superhero Thor. ⚡️
Before Thor was even a thing, the nebula was known under a different name: The Duck Nebula. This is why you might find NGC 2359 labeled as "Duck Nebula" instead of "Thor's Helmet Nebula" in some planetarium software like SkySafari.
The name "Thor's Helmet" ended up being the one to stick around the most, and is now what everyone knows this object as! Sorry ducks! 🐣
We imaged Thor's Helmet three times:
January 2022: Imaged with a small refractor telescope from the city for a total of 61 hours
January 2021: Imaged when filming Episode 15 of Galactic Hunter. This time, we used a 655mm focal length refractor telescope and did a bi-color combination.
January 2019: Our very first light with our monochrome camera (the ASI1600MM) with our 8" reflector telescope.
You can see our best attempts below!
The Seagull Nebula & Thor's Helmet with a Wide Refractor Telescope
January-February 2022, from our Las Vegas backyard
The Giant Vs. The Mighty ⚡️
Look at the picture below. Are your eyes naturally drawn to the huge and bright Seagull Nebula? Did you also notice the much smaller Thor’s Helmet near the bottom right? Don’t be fooled by the difference of size between the two, Thor would totally win in a space fight against a seagull 🐦⚡️ 😅
This is our LONGEST integration time to date… 61 hours!
We beat our previous record of 45+ hours of exposure (The Elephant Trunk Nebula) with this image by spending many, many nights on it.
You can watch our full video about it, attached on the left.
This was very challenging to do because this target was only available for 5 hours max from my backyard. It would be high enough around 8 PM, then get behind trees at 1 AM. I only have narrowband filters in my filter wheel and this is the last large nebula in the sky so after 1 AM each night, the scope would just sit there doing nothing. But it was WORTH IT!
After 12 nights… and long hours of stacking and processing, this is the result!
IC 2177 and NGC 2359 with a small telescope
GEAR USED:
Camera: QHY600M
Telescope: Stellarvue SVX130 for Thor | Meade 70mm APO for Seagull
Mount: Atlas EQ-G | GM1000HPS
Guiding: ZWO ASI 290MM Mini
Accessories: Moonlite Nitecrawler focuser / Pegasus Astro Ultimate Powerbox
Power: Jackery Lithium Battery
Processing: PixInsight with RC-Astro Plugins
ACQUISITION DETAILS:
Total Exposure Time: 11 hours for Thor, 50 hours for Seagull. Total: 61 hours
Exposure Time per frame: 10 minutes
Filters: Chroma 3nm Ha/Sii/Oiii
Gain: 56
Want to follow our exact processing workflow to achieve similar results with your data? Get our PixInsight PDF guide! It contains 97 pages of step-by-step instructions, video walkthroughs, raw data, and our custom process icons!
Thor's Helmet with the QHY600M and SVX130
January 2019
GEAR USED:
Camera: QHY600M
Telescope: Stellarvue SVX130
Mount: Astro-Physics Mach-1
Guiding: ZWO ASI 290MM Mini
Processing: Pixinsight
ACQUISITION DETAILS:
Total Exposure Time: 10.7 hours
Exposure Time per frame: 10 minutes
Filters: Chroma 3nm Ha/Sii/Oiii
Gain: 26
How to Find Thor's Helmet
Thor's Helmet can be found in the constellation of Canis Major. It is fairly easy to find, because it is very close to the brightest star in the night sky: Sirius. From there, simply travel about 8 degrees northeast in order to find the nebula.
Thor’s Helmet is a faint target that is impossible to spot with the naked eye or binoculars. A telescope of at last 6” is required to spot its nebulosity from an extremely dark site, but do not expect to view something impressive. A 10” telescope will reveal some of the shapes in the gases. If you would like to see more of the nebula, you would need to attach a filter to a high power telescope, and only then will you be able to distinguish the iconic shape of the helmet.
Cool Facts about Thor's Helmet
About 30 light-years across
Wolf-Rayet star gives NGC 2359 its glow
Similar to the Bubble Nebula, but more complex
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Single Shot & Processing of Thor's Helmet
Using the ASI1600MM - January 2019
We used three filters to capture Thor's Helmet: Ha, OIII, and SII. Both Ha and OIII gave us impressive single shots (see below for Ha), but SII only showed us a tiny bit of gas.
Single shot of Thor's Helmet with the Hydrogen Alpha filter - 3 minutes at gain 139
The processing was fun, as we decided to do a Hubble Palette workflow. We still have some noise and not enough "orange" in our image, so we really hope adding 3 hours to it will fix that!
Using the QHY600M - January 2021
Wondering what a single 10 minute shot would look like with a better camera and better skills?
On the left below is a 10 minute shot using the OIII filter. On the right is the stack (about 5 hours) image, slightly cropped. Notice how much gas gets revealed thanks to stacking.
Thor's Helmet in OIII. 10 minutes (left) vs. 5 hours (right).
If you are interested in learning how I process all our images, you can download a full PDF "follow along" file that contains 97 pages, a full 1 hour and 45 minutes walkthrough tutorial video, our custom pre-sets and even raw data HERE.
Galactic Hunter Episode 15 - Thor's Helmet
Thor's Helmet is the star of Episode 15! We did our best to make this a fun yet instructive video, and we hope you like it!
You can find the full episode below!
Final Thoughts
Thor's Helmet is definitely one of our favorite nebulae. It is not a difficult target and can be photographed by beginners quite easily!
Thor's Helmet looks great with both a large telescope and wide field. If you own a small refractor and would like to include the Seagull Nebula in your frame as well, go for it!
Would you like a print of our image? Click the pic on the right to get one for your home. Be sure to snap a photo for Instagram and tag us so we can see how it looks on your wall 😃
Have you captured Thor's Helmet Nebula? Attach your image in the comments and let us know your acquisition details!
Clear Skies,
Antoine & Dalia Grelin
Galactic Hunter
GALACTIC HUNTER BOOKS
Really nice to see the evolution of the image, the journey shared is a gift!