Dual-lobed Planetary Nebula in Gemini
The Ha data was quite faint and showed no different features, so I used only the OIII data, colorize to teal blue, for this image. Note two very small patches of nebulosity just to the lower right of the main nebula.
Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27. PEC on.
Exposure: Total exposure time about 12 hours; 33 x 20 mins OIII, plus 15 x 1 min each RGB. All bin 1x1.
Filters: Astrodon 3nm OIII, Type IIi RGB
Date: Data was collected over 9 nights from October 2015 to February 2016
Imaging automation and capture: Sequence Generator Pro
Guiding Hardware: ASI120MM, Celestron off axis guider. Guiding scale 0.46 arcsec/pixel. 1 second guide exposures.
Focusing: Rigel Systems GCUSB/nStep on stock C11 focuser
Guiding Software: PHD2. RA aggressiveness 55, hysteresis 0, Minimum Move 1.4 arcsecs, Max RA 1000, Max Dec 600. Guiding unbinned with ZWO connection. Dec set to hysteresis. Dithering set to Extreme with Settle < 1.2.
Guiding performance: FWHM of subs about 1.8 arc seconds, RMS in PHD about 0.75 arcsecs.
Light pollution: Bortle 8 (white zone, NELM about mag 4.5)
Image scale at capture: 0.6 arcsecs/pixel = f/5.7
Scale of presentation: 0.9 arcsecs/pixel
Processing: Bias, darks, and flats. Stacked and processed with PixInsight, with a few minor modifications in Photoshop. The nebula is OIII, colorized to teal blue, and layered onto an RGB star field in Photoshop.