This is the Crescent Nebula, also known as NGC 6888. It’s is a fun and fantastic target that I worked on this year from June through early August 2021. I took 22 hours of integrations at F7 and another 8 hours with the Hyperstar v3 at F2. The F2 focal length is more like a nice wide 560mm while the F7 is around 1960mm. I neglected to show a visual of the F7 arrangement in this video. Just refer to my Celestron OAG v2 video, its the same arrangement. At one point I redid polar alignment and got it down to 6″ plus clearer and more stable skies came along, lowering hfr and guiding rates.
Equipment used
Telescope: Celestron 11″ EdgeHD
Observatory: NexDome
Mount: iOptron Cem120
PC: Canyon I7 Mini PC
Oag: Celestron
OAG Guidecam
F2: Asi290mm mini Guidscope
F2: 60mm Svbony Guidecam:
Asi174mm mini
Focuser: Rigel nStep
Camera: Asi294mc Pro
Filter drawer: Starizona
Filter: L-Enhance 2″ (mostly), L-Pro 2″ (around 60min out of the 22 hours) Reducer: Celestron F7
I first ran the F7 (and F2) images through AstroPixel Processor to do the stacking (my preferred method when dealing with multiple sessions with multiple sets of flats and dark flats). After that I used PixInsight for processing. Used my usual techniques for processing but this time also used StarNet to remove the stars, then worked on the nebulosity on its own, to try to pull out some extra color on the O3 shell. This worked out fairly well, combined with the color saturation tool.
The F7 arrangement of equipment and OAG etc, was the same as I outlined in the OAG Revisited video (I forgot to include the clip showing the OAG setup in the video)
