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Although it's in Canis Major, I wonder did you happen to look at ngc2359, Thor's Helmet? This is a very weird-looking but not very well known nebula formed by a Wolf-Rayet star. I have only seen it through a telescope, and it benefits greatly from an OIII filter. Is this visible with binoculars?

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Rather than Hijack my own thread about Puppis, I thought I'd open a new thread since Thor's Helmet is in another constellation . Thor's Helmet is magnitude 11.45, so I was thinking it would be borderline in my Saturn III (39x100) binoculars.

I wasn't even planning on observing tonight as I was bit bleary-eyed after doing all the year-end state and Federal tax reporting on 3 organizations I manage . But just before going to bed, I looked out and the skies were clear, and more importantly it was some 30°F warmer than the night I was looking at Puppis (45°F vs. 15°F)! So I put a jacket over my dressing gown, put on some warm boots and went onto the back deck. The sky was reasonably dark for this area (SQM 21.0 - I often see 21.20 to 21.30 on moonless nights).

I took out the Miyauchi 30x77's which are a wonderful Grab&Go combination to scope out the general area of Thor's Helmet in Canis Major. It's not that difficult to get into the area: A line drawn from Sirius to Muliphein (a 4th Mag star just 4.5° East of Sirius) is then extended through Muliphein on the other side, just a little bit less, making a wide oblique angle Northwards. There's a loose grouping of stars in which Thor's Helmet is located.

I was quite surprised to instantly see Thor's Helmet - a hazy patch just 7' away from an 8.7 mag star which is the yellow star below and to the left in this photograph of Thor's Helmet. There's a nice pairing of two lines of stars at right angles to each other (including that yellow star) just next to Thor's Helmet that makes it easy to confirm one is looking at the correct area.

After finding it so quickly, I decided I had to try and catch it handheld in my 18x50's Canon's, so I went back inside, quickly grabbed them and started looking. Sure enough Thor's Helmet was still visible in the 18x50's although I have to say it was at the borderline of what I can catch in these binoculars (and I do spend a lot of time going after really dim objects!).

Knowing exactly where it is now, I've added that to my list of objects to look at when I next take out my 15" scope. I daresay the view with the Ethos and an OIII filter will be a little bit more spectacular, but it'll be tough to handhold that.

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I'd be willing to bet in large part the ability to see this is dependant on dark skies.

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Yes, very definitely the case. I know that I am very lucky to be located where I am in a Blue area. That night was 21.0 on the SQM which is (I'm almost embarrassed to say this...) not that good for this area on a moonless night. I have a conversion formula for SQM to NELM which says 21.0 corresponds to mag 6.5 skies, although I have to say, I have a terrible time coming even close to seeing stuff that faint with the naked eye as I have differentially adjusted contacts (my left eye is corrected more for reading than long distance).

And you will recall that under my best skies here, I have seen both M74 and IC342 in my 10x42mm binoculars from here in N GA (yup, I know, amazing skies, probably my reward for spending 40 years in Urban Chicago !).

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