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The Orion Nebula core 21/12/2017 21:32
(1300 light years)
GSO 0.20 m
Sky-Watcher NEQ-5 Pro SynScan mount
QHY5L-IIC + IR cut filter
f: 1000 mm
300x1" + 248 dark
Total exp: 5 min
Matteo Vacca Milis, Italy http://vaccamatteo.weebly.com/ https://www.astrobin.com/users/matteovacca/
Not that anyone could get fed up with this object...
Date: 01 January 2018
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD
Subframes: 30 x 300s, 100s & 20s H-alpha, 20 x 20s & 100s RGB 2x2 binned, 20 flats for each channel, no darks (hot pixel removal in Astroart instead).
Images were acquired and pre-processed (aligned, stacked, denoised) in AstroArt4, then composited in Paint Shop Pro7.
The Orion Nebula presents quite a challenge to depict because of the wide brightness range of its key features. Many early CCD images of this object as shown on the web "burn out" the "trapezium" region of the four central stars in attempting to show the outlying nebulosity.
I use the "layers" function in PaintShop Pro, stacking the longest exposures on top of shorter ones, and then carefully use the "eraser" tool to remove overexposed areas, leaving the underlying correctly exposed regions to show through. This has to be done with care to avoid introducing obvious processing artefacts.
Whilst the latest image processing programs such as Pixinsight have "dynamic range adjustment" features that can automatically produce an even distribution of brightness, some of the resultant images can seem rather strange to my eyes. Programmes like that are way beyond both my budget and my understanding!
LRGB combination (using the H-alpha stack as the luminance channel) went well in both Astroart and PaintShop Pro. The PSP version was a lot greener than the Astroart one (though you can “weight” colours to compensate for CCD sensitivity at different wavelengths), but I preferred the PSP output as it hinted at the greenish hue of the nebula that is so clearly discernible though the eyepiece.
All of the brighter features seen in the above image show clearly through my VC200L and a 25mm eyepiece. The central trapezium of four stars shines brilliantly against a bright silvery background, which fades into the convoluted greenish wings of the surrounding nebula. The dark channel between the main portion of the nebula and the upper candle-flame is clearly seen.
I strove to retain all of these key features in the image above, as well as highlight the extended nebulosity that the eye cannot see.
Any comments, criticisms or suggestions gratefully received...
One night after complaining on the forums that observing opportunities are so few and far between in the UK during winter and I look up to see clear skies and a blindingly bright moon. My preferred targets are DSOs but having recently bought a Baader Neutral Density Moon filter (0.9) I thought it might be a great time to try it out. I'd also recently bought that thingy that lets you attach your phone to the eyepiece and so I took the picture below and I'm fairly pleased with the result. I thought that the blue fringe of doom was exclusively a refractor thing which is why I was surprised to see the blue fringe in the picture.
I have owned my Skyliner 200p Dobsonian for around ten years and so it might surprise you to know that I have never managed to see the Orion Nebula through my telescope, or any other telescope for that matter; so last night, with the moon 96% of full I thought I'd give it a try. Less than ideal conditions you might say but I have to tell you, it was still spectacular! I was able to see a surprising amount of detail and I also worked out (at long last) which time of year and what time of night I can see the whole of Orion from my back garden (mid to late January onwards at around 11pm) rather than the utterly light polluted front garden. I cannot wait for a moonless (clear) night so I can sketch the nebula! I did also discover that my collimation efforts were less than stellar (pun intended) and so, back to the drawing board.
Overall it was a fantastic night's observing! I was able to spend a good while not just looking at the nebula but observing it and teasing out as much detail as I could using the usual old tricks. The night was clear but all my back garden observing is done over the neighbours' houses, so heat shimmer and therefore focus was an issue. I actually used my Baader Neodymium filter to reduce the effects of light pollution and increase contrast which it did very well. I'm seriously itching for a clear moonless night!
By the way if anyone can recommend a good observing chair my back would be very grateful
King of the winter night sky -Orion Nebula
As the part of our galaxy lies around 1340 light years from us and is the closest region of massive star formation to Earth.
Only 27 frames as the clouds were covering all sky as soon as I arrived..
Scope: Skywatcher EVOSTAR 80ED DS-Pro
Mount: AZ EQ6-GT
Filter Optolong L-PRO MAX Luminosity
Guiding camera: ZWO ASI120MC
Guiding scope: SW 9x50 finderscope
27x300s exposure at -10°C (135min total) 2h 15min