This faint nebula, Abell 21, is located in eastern Gemini near the more famous Eskimo planetary. Quite large, fills the BigDog
fov at f6. Conditions suspect, seeing average at best, transparency colored by passing hi-cirrus, temp about 40F, but clear none the less, a rarity this winter. Total exposure an hour and a half, but could add Oiii for another hour, but not a lot of it in this thing.
Specifics; Meade 16 LX200 at f6.2 with Starizona reducer for 2500mm efl. Exposed in Atik 460ex mono for 12/5 min
Ha, 5/2 min for green and blue, used 10 minutes of
Ha for pseudo-red. All sub-images binned 2x2 for 0.7 "/pixel. Bad pixel map applied to all subs nothing else. Captured and stacked in Nebulosity, final in Photoshop using layers for
RGB, Luminosity (
Ha), and pseudo-hydrogen color (hot pink) for nebula.
Clear skies,
Steve