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The Ring Nebula in Lyra; one of my favourite celestial objects and one I look forward to
every year. Not only is it bright and colourful, this beautiful object is a perfect example
of what will happen to our Sun in a about four billion years. If you look closely you can
just see the white dwarf in the centre. 

12 x 8 minute exposures at 400 ISO
11 x dark frames
10 x flat frames
21 x bias/offset frames (subtracted from flat frames only)

Captured with APT
Guided with PHD
Processed in Nebulosity and Photoshop

Equipment:
Celestron NexStar 127 SLT
GoTo AltAz mount with homemade wedge
Orion 50mm Mini Guide Scope
ZWO ASI120 MC imaging and guiding camera
Canon 700D DSLR

M57_04.jpg

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The summer skies are just around the corner- all those short nights of bright skies and faint objects lost in a sky that looks like perpetual twilight but the compensation is we get M27, M57 & the wild duck cluster M11 as well as the veil nebula & the vast Cygnus star clouds which from my location I only see the stars & no milky way.

Sorry I digress on to your image. The problem with M57 is whilst its a lovely object it is also very small so long focal length telescopes do it justice as its very bright so the extra image scale smooths out the "shock" of having a big lump of small very bright data swamping the CCD array. The small image scale for your system means that you have lost detail & there is a lot of noise around the nebula. I don't know how many subs you took but its not enough. Reading your description it sounds like you have lots of flats & darks but the noise in your image shows either an unlucky imaging session or not enough subs which is indicative of the fuzzy edge around the nebula. The focus is also slightly out so that will need attention perhaps a focusing mask would be a help. I personally have not a good image of M57 as it was the first object I imaged with the C11 when I began imaging and it came out awful & I never recovered from the shock. Please don't interpret this as me being a hypocrite but I know you can do much better with your equipment.

I might have a go at a re-image this season. So off you go then- take loads of subs of perhaps no longer than 90-120 secs, make sure your focus & tracking is good & remember to colour calibrate as perhaps you have a bit more green than is required. More subs mostly makes the noise go away or at least makes it easier to remove from images so that speckly ring around the nebula would vanish as the S/N increases.

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      Messier 57 is is just coming into a position for a decent look around 11 30 pm. IT is a colourful object and I thought it would give me a good target with which to practice my colour developing in PS/Lightroom. I have read so much about how to produce a LRGB image from the four stacked/calibrated luminance, red, blue and green images,  a lot seems contradicatory and some, when followed, gave me colour yes, but not as we know it. I am sure a fair chunk must be put down to me. Anyway, I now have a work flow which gives me colour, sometimes resembling what other people have obtained. Progess of sorts.
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      NASA: M57, or the Ring Nebula, is a planetary nebula, the glowing remains of a sun-like star. The tiny white dot in the centre of the nebula is the star’s hot core, called a white dwarf. M57 is about 2,000 light-years away in the constellation Lyra, and is best observed during August. Discovered by the French astronomer Antoine Darquier de Pellepoix in 1779, the Ring Nebula has an apparent magnitude of 8.8 and can be spotted with moderately sized telescopes.
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