NGC 663

NGC 663Click image for full size version

August 28, 2022

NGC 663 lies in Cassiopeia and covers about half a Moon width on the sky. Like most open clusters, it is perfect for imaging under a full Moon. NGC contains about 400 stars and lies at a distance of about 6,850 light years – rather close compared to most of my targets.

Tekkies:
Acquisition, focusing, and control of Paramount MX mount with N.I.N.A., and TheSkyX. Focus with Optec DirectSync motors and controller. Equipment control with PrimaLuce Labs Eagle 4 Pro computer. All pre-processing and processing in PixInsight. Acquired from my SkyShed in Guelph. Very good transparency and average seeing. Acquired August 12, 2022, in a single near-full Moon night.

Sky-Watcher Esprit 150 f/7 refractor and QHY16200A camera with Optolong UV/IR filter

Tak FSQ-106 @ f/5 (530mm), QHY-367C Pro One-shot colour with Optolong UV/IR filter 
 
41x5m Lum = 3hr25m
41x5m OSC = 3hr25m
Total: 6hr50m
Image scale 0.565 arcsec per pixel 
 
       
Data Reduction and Cleanup

The WeightedBatchPreProcessing script was used to perform calibration, cosmetic correction, weighting, registration, local normalization, integration and Drizzle integration of all frames.

DynamicBackgroundExtraction was applied to the luminance and OSC masters.

Colour
Colour Calibration: ColorCalibration was used to calibrate the OSC master. 

Linear Noise Reduction: NoiseXterminator was used to reduce noise in the background areas with settings Amount=0.9 and Detail=0.15 

Stretching:  HistogramTransformation was applied to make a pleasing yet bright image.

Luminance
Linear Noise Reduction: NoiseXterminator was used to reduce noise in the background areas with settings Amount=0.9 and Detail=0.25 

Stretching: HistogramTransformation was applied to make a pleasing yet bright image. 

Combining Luminance and Color Images
Luminance addition: LRGBCombination was applied to replace the lightness of the RGB image with the Luminance master.

Additional Processing

Nonlinear Noise Reduction: NoiseXterminator was used to reduce noise in the background of the image with settings Amount=0.9 and Detail=0.25.  

Final Steps: Background and star brightness, contrast and saturation were adjusted in several iterations using CurvesTransformation with masks as required.  ICCProfileTransformation (sRGB IEC61966-2.1; Relative Colorimetric with black point compensation) was applied prior to saving as a jpg.