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A retired Welshman living in wonderful Plymouth in SW England, I’m a family man, novice sailor and boat builder, astrophotographer and motorhomer. With a passion for all things to do with education and the sea and skies above, I have a sense of adventure and innate curiosity. I write three blogs. ‘Arwen’s Meanderings’ charts my learning to sail a self-built John Welsford designed ‘Navigator’ yawl. Look out for her accompanying YouTube channel www.YouTube.com/c/plymouthwelshboy . ‘UnderSouthWestSkies’ follows my learning journey as I take up astronomy and astrophotography; a blog for beginner’s new to these hobbies, just like me. ‘Wherenexthun’, a co-written blog with my wife Maggie, shares how we ‘newbies’ get to grips with owning ‘Bryony’ an ‘Autosleeper’s Broadway EB’ motorhome, and explores our adventures traveling the UK and other parts of Europe. Come participate in one or more of our blogs. Drop us a comment, pass on a tip, share a photo. I look forward to meeting you. Take care now and have fun. Steve (and Maggie)
Showing posts with label NGC 6888 The Crescent Nebula. Show all posts
Showing posts with label NGC 6888 The Crescent Nebula. Show all posts

Monday, 26 May 2025

Imaging session - My first effort on the NGC 6888 The Crescent Nebula

First visit to this astronomy/astrophotography blog? Well, firstly a warm welcome to you and thanks for stopping by. After reading this post, if you want to find out more about me and this blog, why not visit my introductory page at https://undersouthwestskies.blogspot.com/2025/01/welcome-to-my-new-astronomyastrophotogr.html You can also browse other posts by using the search bar or the blog post list on the right hand side and I'd really like to hear from you via the comment boxes. Drop me a tip, an observation or a question. Take care and clear skies to you. Steve

 I am slowly getting to grips with the idiosyncrasies' of the EQM-35-Pro.  Balancing in DEC is straightforward as it moves and rotates easily. Balancing in RA is tricky.  The grease used by Skywatcher is gunky and makes rotation stiff. 

Anyway, here are the acquisition details of my latest effort - NGC 6888 The Crescent Nebula.

equipment: 

Canon 800 D DSLR astro-modded

WO Zenithstar 61ii refractor with field flattener

ASIair mini with ZWO 120mm mini guide cam and RVO 32mm guide scope

Celestron Lithium Pro power bank

EQM-35-Pro

photograph details: 

lights: 60 x 180" at ISO 800

20 each of flats, biases and dark frames


And here are the photos, after post editing in SIRIL, GraXpert and Affinity Photo: 

alt="NGC 6888 Crescent Nebula"
I never understand how I manage to get a different result on exactly the same data every time I use SIRIL. Baffling! 

alt="NGC 6888 Crescent Nebula"

alt="NGC 6888 Crescent Nebula"
and here are two further processed from the originals. If you asked me what I did - I have no idea! 

alt="Starless image of NGC 6888 Crescent Nebula"

So, NGC 6888 - around 5000 light years away and discovered by Herschel in the late 1700's.  An emission nebula in the constellation Cygnus, it is formed by fast stellar winds from the Wolf-Rayet star WR 136. 
This stellar wind collides with and energises a slower moving wind ejected by the star when it became a red giant some 400,000 years ago.  The result of this collision is a shell and two shock waves. 

Postscript:

I have done some follow up post editing and here is my final image from this data set:

alt="NGC 6888 Crescent Nebula"




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