Medusa Nebula in Narrowband

[Mike Lewis]

The Medusa Nebula (Sh2-274, Abell 21) is a low surface brightness planetary nebula in the constellation Gemini, originally discovered by George Abell in 1955. It is estimated to be at an approximate distance of 1,500 light years from us.

This is small enough that it is probably more appropriately imaged with a larger focal length scope, but since scope swapping with my remote setup is a bit complex, I decided to give it a try anyway.

This narrowband image that has been cropped in significantly to show more detail. I also did not like the results I was getting from my RGB star data, so this is using narrowband stars, mixed to look more RGB-like. Data collection details follow. A larger version can be found on Astrobin here: https://app.astrobin.com/u/mlewis?i=72voaa Thanks for looking and all comments,critiques and questions are most welcome.

Equipment:
QHY268M Camera @ -5C and
Gain:56 Offset:25
Software Bisque MyT Mount
Stellarvue SVQ100 Astrograph Refractor, 580mm @ f/5.8
Antlia Pro Filters (3nm narrowband)
QHY OAG-M/ASI290MM

Software:
Pixinsight Commercial Version 1.9
Lightroom CC
Photoshop CC
N.I.N.A. Control Software
BlurXTerminator (Russell Croman)
StarXTerminator (Russell Croman)
NoiseXTerminator (Russell Croman)

Light Frames:
Gain 56 / Offset 25
Ha: 32 x 600 secs (5 hrs 20 mins)
OIII: 28 x 600 secs (4 hrs 40 mins)
SII: 31 x 600 secs (5 hrs 10 mins)

15 hrs 10 mins total

Dark Frames:
10 x 600 secs (1 hr 40 mins)

 

[JimFox]

I am finally back home in California and trying to catch up here.

I like what you got here. I captured Medusa a while back, but I don't recall if I posted it or not. I will need to go look. But I like what you got.

I agree the stars do not look very RGB, they look mostly to be blue, so that's odd.

And what's great with our processing tools today, cropping is so much more viable then it used to be. Did you run this through Enhanced mode in ACR or one of the other image enlargers? Most of them pretty flawlessly double the resolution of an image, which is great when having to crop a lot.

 

[Comet Hunter]

Tough target and you seemed to nail it! Nicely done

 

[Mike Lewis]

I am finally back home in California and trying to catch up here.

I like what you got here. I captured Medusa a while back, but I don't recall if I posted it or not. I will need to go look. But I like what you got.

I agree the stars do not look very RGB, they look mostly to be blue, so that's odd.

And what's great with our processing tools today, cropping is so much more viable then it used to be. Did you run this through Enhanced mode in ACR or one of the other image enlargers? Most of them pretty flawlessly double the resolution of an image, which is great when having to crop a lot.

Jim,

I ended up drizzling it 2x in PixInsight, which I frequently do with my refractor images. So that gives me plenty of size to work with later.

I am sure the mostly blue stars are from the NB stars to RGB script I used. Not perfect, but better than leaving them unchanged, to my eye at least.

ML