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The Hole in the Trees Skybox | all galleries >> Deep Sky >> Planetary Nebulae > Abell 8
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Abell 8

PK 167-0.1 (PNG 167.0-00.9) in Auriga

This extremely faint planetary (mag 16.6, dia. 60) is mostly Ha, so I used Ha colorized to pure red for the nebula and the faint wisp of nebulosity near it. A few hours of OIII was also taken, but it was just a faint version of the Ha and so was not used.

Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27. PEC on.
Camera: SXVR-H694
Exposure: Total exposure time about 8.75 hours; 24 x 20 mins Ha, plus 14 x 1 min each RGB. All bin 1x1.
Filters: Astrodon 5nm Ha, Type IIi RGB
Date: Data was collected over 7 nights from November 2015 to January 2016
Imaging automation and capture: Sequence Generator Pro

Guiding Hardware: ASI120MM, Celestron off axis guider. Guiding scale 0.92 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 Ha, colorized to pure red, and layered onto the star field in Photoshop.

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