It's just a big ball of stars. I decided to try out a broadband target while waiting for some others to come into my view. Thanks to my wonderful horizons and the fact that this this is at dec +30 I only had a half hour window per night to shoot it. Still pleased with the results, especially with my light pollution. Captured over 4 nights from December 14-19, 2023 from a Bortle 9 zone.
Places where I host my other images:
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TPO 6" F/4 Imaging Newtonian
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Orion Sirius EQ-G
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ZWO ASI1600MM-Pro
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Skywatcher Quattro Coma Corrector
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ZWO EFW 8x1.25"/31mm
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Astronomik LRGB+CLS Filters- 31mm
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Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
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Agena 50mm Deluxe Straight-Through Guide Scope
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ZWO ASI-120mc for guiding
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Moonlite Autofocuser
Acquisition: 2 hours 32 minutes (Camera at unity gain, -15°C)
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Lum - 77x60"
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Red - 27x60"
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Green - 24x60"
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Blue - 24x60"
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Darks- 30
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Flats- 30 per filter
Capture Software:
- Captured using N.I.N.A. and PHD2 for guiding and dithering.
PixInsight processing:
Preprocessing
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BatchPreProcessing
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StarAlignment
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ImageIntegration per channel per panel
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DrizzleIntegration (2x, Var β=1.5) per panel per channel
Narrowband Linear:
- DynamicBackground Extraction
duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
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BlurXterminator for star correction
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ArcsinhStretch + HistogramTransformation to bring nonlinear
RGB linear
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DynamicBackground extraction as above
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ChannelCombination to combine R G and B stacks into color image
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SpectroPhotometricColorCalibration
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BlurXterminator star correction
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HSV Repair
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ArcsinhStretch + HT to bring nonlinear
Nonlinear:
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LRGBCombination with stretched RGB pic and stretched L pic as luminance
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shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with lum masks)
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DeepSNR
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Slight SCNR Green
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More Curves
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Resample to 70%
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DynamicCrop again
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Annotation