Hadn't tried the Cat's Eye in 3 years, remembering it was a pretty difficult target. But conditions looked favorable so I decided to give it a try. Found it by synching from δ Draconis, with a lot of help from Astrotortilla. I can't see any of the outer halo in the individual subs no matter how hard I stretch, so processing this is going to be interesting. Some gusty wind and quite warm; CCD starts at 25.5 °C and has only cooled to 22 °C or so by 2:30. Imaged up to the meridian and performed a flip, then re-synched with Astrotortilla and re-acquired. Guiding has been marginal tonight. This was indeed difficult to process: it had to be stretched much more aggressively than I usually try, followed by very aggressive curves/levels in Photoshop to clip out the color noise in the background. Bloating and overexposure of the central star is also a problem I have not fixed. This object would really benefit from narrowband filters and/or truly dark sky. I have the sky I have, and I don’t have the OIII/SII filters needed for this, so this is the best I can do at this point.

Date: 18 Jun 2015

Subject: NGC 6543, Cat’s Eye Nebula

Scope: Orion ST-80+High Point Scientific Coma Corrector

Filter: Baader Fringe Killer

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.5.0 (Win 7 ASCOM)

Camera: DSI IIc no cooling (about 22 °C)

Acquisition: Nebulosity 4.0.2, no dither

Exposure: 34x480 s

Stacking: Neb 4.0.2, bad pixel map, bias included, 33 flats, histogram match, deBayer & square. DSS 2x drizzle, 1.5σ κ-σ stack.

Processing: StarTools 1.3.5.289 Crop; Wipe: 85%; Develop: 75.54%; HDR:Equalize; Color:Scientific 200%; Deconvolute 3.5 pix; Life:heavy; Track 10 pix, smoothness 95%; Magic, shrink 3 pix. Photoshop CC 2014 + Carboni Astronomy Tools Deep space nr; several cycles of Levels/Curves; Increase star color; Space nr; all of the above was using layer masks; Color range select purple & desaturate to get rid of more nasty color noise; Liquify/pucker to debloat large stars; Less crunchy/more fuzzy; Astroframe.