PK 173-05.1 (PNG 173.7-05.8) in Auriga


This image uses OIII for the nebula. About 14 hours of Ha was also taken, but was almost completely identical to the OIII, and was not used. The one significant difference is an Ha extension that does not appear in OIII. The Ha image can be viewed here.


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 12 hours; 30 x 20 mins OIII, plus 20 x 2 mins each RGB. All bin 1x1.
Filters: Astrodon 3nm OIII, Type IIi RGB
Date: Data was collected over 15 nights from August to November 2015
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 OIII, colorized to teal blue, and layered onto the star field in Photoshop.