NGC 7129
Also Known as: Cr 441
Object Type: Reflection Nebula
Constellation: Cepheus
Distance from Earth: 3,300 light years
Apparent Magnitude: 11.5
Coordinates: RA 21H 42M 56S DEC 66 deg 06 min 12 sec
Actual Size: 6 light years in diameter
Apparent Dimensions: 7 arc-minutes x 7 arc-minutes
--------------------------------------------------------------------------
Environmental Data
Date: July 21, 2025 Start Time: 9:07PM End Time: 4:36AM SQM: 16.13
Moon Age: 26.0 days Moonrise: 1:36AM Moon Illumination: 13.4%
Temperature: 70 degrees F Humidity: 59% Dew Point: 54.7 degrees F
Location: Westport, Massachusetts 02790 Sky Condition: Mostly clear, high clouds later
Comment:
--------------------------------------------------------------------------
Imaging Scope Data
Mount: iOptron CEM120 Camera: ZWO ASI2600 monochrome Focuser: Optec QuickSync FT20
Telescope: Celestron 11 inch SCT Edge Focal Length: 1960mm
Focal Reducer/Field Flattener: 0.7 focal reducer Dew Heater: Kendrick dew strip
Filter Wheel : ZWO EFW 7 position 2 inch Filter(s): Baader Lum CMOS optimized 2 inch, Baader RED CMOS optimized 2 inch, Baader GREEN CMOS optimized 2 inch, Baader BLUE CMOS optimized 2 inch
Rotator: Pegasus Falcon 2 Power Control: Pegasus Ultimate Powerbox V2
Imaging Software
Mount: iOptron Commander Focuser: Optec FocusLynx Commander
Imaging: Sequence Generator Pro Platesolve: ASTAP Rotator/Control: Pegasus Unity Platform
Imaging Status
Imaging Software: Sequence Generated Focus HFR 2.86 Platesolve: Success on 3rd attempt
Guide Scope Data
Telescope: Stellarvue SVX130 refractor Camera: ZWO ASI290 Focuser: Optec DirectSync SV35
Dew Heater: Kendrick dew strip Software: PHD2 Exposure: 2 sec Binning: 1x1 Tracking Result: 0.55 arc-seconds RMS
--------------------------------------------------------------------------
Images Taken
Number of light frames (LUM): 30 Duration: 2 minutes Gain: 100
Number of light frames (Red): 60 Duration: 2 minutes Gain: 100
Number of light frames (Green): 60 Duration: 2 minutes Gain: 100
Number of light frames (Blue: 45 Duration: 2 minutes Gain: 100
Camera Temperature: 0 degrees C Binning: 1x1 F-Stop: 7.0
Total Integration Time: 6.5 hours
--------------------------------------------------------------------------
Number of flat frames (LUM): 25 Duration: 0.027 Gain:100
Number of flat frames (Red): 25 Duration: 0.076 Gain: 100
Number of flat frames (Green): 25 Duration: 0.047 Gain: 100
Number of flat frames (Blue): 25 Duration: 0.0954 Gain: 100
Flat Field Illumination: All-Pro 'Spike-a-Flat Field standard' illuminated panel
--------------------------------------------------------------------------
Number of Dark frames: 50 (from library) Duration: 2 minutes Gain: 100
Number of Bias frames: 50 (from library) Duration: 0.001 seconds Gain: 100
--------------------------------------------------------------------------
Imaging Processing
Imaging Processing Software: PixInsight
Processes utilized: Linear - calibration/integration:
For each of the LUM, RED, GREEN, and BLUE lights: Flats ImageCalibration with Master Bias, Flat ImageIntegration, Images ImageCalibration with Flat Master & Dark Master, SubFrameSelector
StarAlign all calibrated lights using best LUM image as reference, ImageIntegration of each of the LUM, RED, GREEN, and BLUE sets
Linear - Background extraction, Color correction, deconvolution, noise reduction:
LUM GradientCorrection, BlurXTerminator, NoiseXterminator
RED/GREEN/BLUE AutomaticBackgroundCorrection, ChannelCombination to create color image using only Red/Green/Blue, ImageSolve, SpectroPhotometricColorCalibration, BlurXTerminator, NoiseXterminator, DynamicCrop
Non-Linear:
LUM: GeneralizedHyperbolicStretch script, HistogramTransform to darken background, MultiScaleLinearTransform to sharpen, DynamicCrop
COLOR: GeneralizedHyperbolicStretch script, DynamicCrop, Curvestranformation to increase color saturation, SCNR to reduce green artifacts.
ImageBlend script to combine LUM and COLOR masters, SCNR to further reduce green cast in one corner, CurvesTransformation for Saturation
Notes: Observatory computer reset at about 2AM forcing use of the stored sequence in SGP to restart and complete. The last set of images were the green channel and this is when high clouds rolled in.
Click Below Image for Full Size:
Click to Return to Home Page