Casitas de Gila, Gila, NM, October 19 - 20, 2023

IC 59 and IC 63 are reflection nebulae in the constellation Cassiopeia.  The nebulae are about 600 light years distant from Earth.  The hot, bright star gamma Cassiopeiae is three to four light-years away from the dust and gas clouds.  The intense light from the blue star is reflected by the dust.  There is also a large gas cloud with a hydrogen-alpha emission caused by the star’s intense UV radiation.

For this image, I captured as much data in 9 hours as possible on my last night of imaging in New Mexico.  While I had sufficient Luminance, Red, Green, and Blue filter subframes, I ended up with only one hour of Ha filter data.  So, I decided to process the image anyway, as I was returning home to the cloudy skies of Oregon.  During image processing in PixInsight, I tested the latest update to determine if several serious problems had been resolved; 1) the ImageSolver script now functions correctly with 2x drizzled masters. 2) SPCC also works correctly on 2x drizzled images. 3) the latest release of GraXpert with AI-based gradient removal worked well.  However, I used the CopyCoordinates script to copy the astrometric solution from the before image before using SPCC. 4) StarXTerminator still failed to remove large and medium sized stars properly from 2x drizzled images.  I had to abandon the use of drizzled data for this target.  With only 6 10 minute subframes, I was very aggressive in denoising the Ha master using NoiseXTerminator.  I used a two-step process to combine starless, stretched Ha with RGB, and Ha with Luminance images, iterating to achieve a decent result.  The sharpened Ha-Lum image was combined with a blurred HaRGB image.  I then used Photoshop to tweak the image, especially the background around gamma Cassiopeiae.  The RGB stars were carefully stretched to keep gamma Cassiopeiae relatively small.  The stars were then combined with the HaLum-HaRGB starless image.

Imaging details:

Stellarvue SVX102T refractor with 0.74x focal reducer (FL = 528mm, f/5.2)
ZWO large off-axis guider with a ZWO ASI 174MM mini guide camera
Losmandy G11 mount with Gemini 2
ZWO ASI 2600MM Pro cooled monochrome camera (-10C)
Chroma 36mm Hydrogen-alpha, Oxygen-III, Sulfur-II, Red, Green, and Blue filters
Equatorial camera rotation: 0 degrees

Software:    Sequence Generator Pro, ASTAP plate solving, PHD2 guiding, 
    Losmandy Gemini ASCOM mount control and web client interface,
    SharpCap Pro for polar alignment with a Polemaster camera,
    PixInsight 1.8.9-2,
    Photoshop 2024

Hydrogen-a 10 min x 6 subframes (60 min), Gain 100, Offset 32, 1x1 binning
Luminance  2 min x 120 subframes (240 min), Gain 100, Offset 32, 1x1 binning
Red             4 min x 18 subframes (72min), Gain 100, Offset 32, 1x1 binning
Green          4 min x 18 subframes (72 min), Gain 100, Offset 32, 1x1 binning
Blue            4 min x 18 subframes (72 min), Gain 100, Offset 32, 1x1 binning

Total integration time: 8.6 hours