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IC 2177 - The Seagull Nebula Narrowband Astrophotography with Thor's Helmet

Updated: May 17

IC 2177 is a large nebula that can be found 3,650 light-years away in Monoceros. It is a great target for both broadband and narrowband imaging, and is very close to the much smaller Thor's Helmet Nebula.

Object Designation: IC 2177

Also known as: The Seagull Nebula

Constellation: Monoceros

Object Type: Emission Nebula

Distance: 3,650 light-years away

Magnitude: 15.2

Discovered in: Late 1800's by Isaac Roberts

The Seagull Nebula IC 2177 in Infrared taken by the Hubble Space Telescope NASA

The photo on the right is an infrared mosaic of the Seagull Nebula taken by NASA's WISE Telescope in 2010. It spans about seven times the size of the full moon, and shows several bright active regions of star-forming activity.

We captured the Seagull Nebula twice:

  • From our backyard with our small refractor telescope where we also included Thor's Helmet in the same frame

  • Using our friend Craig's data from his observatory in Utah to get a nice close-up view of the nebula

See both results below!


The Seagull Nebula & Thor's Helmet with a Small Refractor telescope

January-February 2022, from our Las Vegas backyard

The Giant Vs. The Mighty ⚡️

Your eyes may be naturally drawn to the huge and colorful Seagull Nebula… but did you also spot the much smaller Thor’s Helmet on the bottom right? Don’t be fooled, 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

The Seagull Nebula and Thor's Helmet Nebula with a small refractor telescope from the city in narrowband


Camera: QHY600M

Telescope: Stellarvue SVX130 for Thor | Meade 70mm APO for Seagull

Mount: Atlas EQ-G | GM1000HPS

Guiding: ZWO ASI 290MM Mini

Accessories: Pegasus Astro Ultimate Powerbox

Power: Jackery Lithium Battery

Processing: Pixinsight with RC-Astro Plugins


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


The Seagull Nebula with the ASI6200MM and FSQ-106 using PixInsight

January 2022, from Utah Desert Remote Observatories

The rig used to image IC 2177 - Utah Desert Remote Observatories
The rig used for this image - Utah Desert Remote Observatories

I recently met an astrophotographer from Utah, Craig, who has an observatory under a Bortle 2 sky! You can visit Utah Desert Remote Observatories' website and book some time on the available telescopes if you'd like to image from the site.

Soon, you'll also be able to host your own telescope there if you are looking to house your own rig under a dark site and connect to it remotely whenever you want to image!

Craig had the idea of doing a fun collaboration where we’d shoot a target together using his observatory gear, and process that same data using different software. Craig is a master of Photoshop, he has used the software professionally for years, and is very experienced with it.

I don't consider myself a master of PixInsight (I mean... who really is, besides Adam Block and a few others? 😅), but I would say I'm pretty good at it.

And so the goal was to compare our processing results (his Photoshop vs my PixInsight). Below is my result! Keep scrolling to see his!

IC 2177 with the ASI6200MM

The Seagull Nebula in narrowband

Want to process your images following our own workflow? Download our guide HERE!


Camera: ZWO ASI6200MM

Telescope: Takahashi FSQ-106

Processing: Pixinsight with RC-Astro Plugins


Total Exposure Time: 9 hours

Exposure Time per frame: 10 minutes


Craig's Seagull Nebula using Photoshop

And here is Craig's attempt at processing the Seagull Nebula, this time using Photoshop! The color palette used is slightly different than mine, and I'm honestly in love with the colors he was able to bring out in his image. I am a fan of the Cyan hue turning into green as you go from top to bottom.

Craig also chose to crop the image to make it a square format, so that the eyes are fully drawn to the rich amount of gas in the nebula.

We'll have a video about this topic coming out soon!

The Seagull Nebula processed using Photoshop - Craig Stocks

The Seagull Nebula processed using Photoshop

What do you think of this image? Let us know in the comments! Keep scrolling to see what the single shots looked like for each channel.


Thor's Helmet - A Small but Mighty Nebula Nearby

Thor's Helmet (NGC 2359) is a cloud of interstellar gas that looks exactly like Thor’s Helmet. It lies very close to the Seagull Nebula and can fit in the same frame if using a small telescope. It is faint, but the colors in the gases have no issue showing on camera when taking long exposures!

NGC 2359 gets its glow from a massive Wolf-Rayet star (WR7) that will soon turn into a supernova.

We imaged Thor's Helmet by itself recently and also made a full video about it!

Also, be sure to check out our full blog post about Thor's Helmet to see our results!


The Seagull Nebula Bow-Shock - A Shockwave with Unknown Origins

The Shockwave in IC2177 - Galactic Hunter
The Shockwave in IC2177 - Crop from our image

If you look closely near the center of our image, slightly to the right, you should be able to spot a bright star with a strange arc-shaped line of gas just above it.

This is commonly known as the "Bow shockwave" in IC 2177. It is believed to come from the interaction between the interstellar dust within the nebula, high radiation winds, and gas expelling from the double star system "FN CMa".

The exact origin is still not very clear, but we might learn more about it in the years to come!

I was able to find a scientific paper from Astronomy & Astrophysics where the authors go in-depth about the composition, shape, and potential origins of the IC 2177 bowshock. If you are interested, you can read this 15-pages paper for free by clicking HERE.

IC 2177 shock wave paper about composition and origin
Screenshot from the scientific paper. Credit: Astronomy & Astrophysics


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Locating IC 2177 in the Night Sky

How to find the Seagull Nebula in the night sky, map

The Seagull Nebula can be found in the constellation Monoceros. It can be seen following the famous Orion as it rises in the sky. IC 2177 is very close to the edge of Monoceros and lies just by Canis Major.

It is very simple to find thanks to the brightest star in the night sky: Sirius. Once you spot Sirius, the nebula can be found just slightly North to it. It is extremely close to the Messier cluster M50, as well as the popular Thor's Helmet Nebula. it is also not far from the Rosette Nebula, the Cone Nebula, and more.

The Seagull Nebula is one of the last nebulae available in the sky until Galaxy Season starts (Spring). For this reason, this is often the last target amateur astrophotographers tackle to end their Winter imaging.


Single Shots & Processing of the Seagull Nebula

Are you curious to know how much signal the HA, SII, and OIII filters yielded in our 10-minute single shots? Just like we do for almost all our images, we included these below so that you know what to expect before imaging it yourself!

In case you didn't know, we have a full page dedicated to showing you how much signal you can expect from each filter for ALL narrowband targets in the night sky. Be sure to bookmark it as it is a great resource to have in the long term!

The Seagull Nebula, single 10-minute images for HA, SII, and OIII

Obviously, the HA data, visible on the left, was more prominent than the SII and OIII channels. This is typical of emission nebulae, which are often rich in Ha, and so not surprising at all.

A Starless version of the Seagull Nebula - IC 2177
A Starless version of the Seagull Nebula

Processing the Seagull Nebula was fun, but I did have trouble with the stars! I fell in love with the starless version of the object, which looks awesome as you can see on the left! Such a clean and beautiful image.

The nebula itself was simple to process once I removed the stars with StarNet, but when re-applying the stars, the overall image looked very messy and I couldn't figure out why... until I took a closer look at the star mask.

The mask used for the stars was taken from an RGB master made from about 20 RGB frames. Upon zooming in very close on that master file, I realized that the stars looked bloated and slightly elongated. This is because a few of the frames that I stacked were out of focus. I started from scratch and only selected the best 8 frames to get my RGB master, which made a huge difference in the end. The stars looked way smaller and crisper and made for a much cleaner star mask.


Final Thoughts

IC 2177 is one of my favorite Winter nebulae, and also one of the last ones available in the sky before disappearing and letting Spring "Galaxy" season take over. It is very large, making it a great target for beginner astrophotographers who own a small wide telescope. It is also easy to capture using both a one-shot color camera, DSLR, or monochrome camera with narrowband filters.

Astrophotography print Thor's Helmet and Seagull Nebula

If you plan on imaging the Seagull Nebula in broadband, be sure to escape the city light pollution first and find a dark site! We recommend Bortle 4 or better.

Would you like a print of our image? Click the pic on the left 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 the Seagull Nebula? Attach your image in the comments and let us know your acquisition details!

Make sure to follow us on Facebook, Instagram, and YouTube to stay up to date with our work!

Clear Skies,

Galactic Hunter

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