NGC 40
Common Name: Bow-Tie Nebula
Also Known as: Caldwell 2
Object Type: Planetary Nebula
Constellation: Cepheus
Distance from Earth: 1,619 light years
Apparent Magnitude: 11.6
Coordinates: RA 00H 13M 01.017S DEC 72 deg 31 min 19.03 sec
Actual Size: 1 light year in diameter
Apparent Dimensions: 38 arcseconds x 35 arcseconds
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Environmental Data
Date: August 3 and August 7, 2025 Start Time: 8:55PM / 9:00PM End Time: 3:29AM / 1:52AM SQM: 17.56 / 17.97
Moon Age (Aug 3): 8.7 days Moonset: Moon Illumination: 63.9%
Temperature: 67.8 / 67.5 degrees F Humidity: 63% Dew Point: 54.7 degrees F
Location: Westport, Massachusetts 02790 Sky Condition: Clear
Comment:
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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 3.31 / 2.34 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: 0.5 arc-seconds RMS
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Images Taken
Number of light frames (LUM): 45 / 40 Duration: 2 minutes Gain: 100
Number of light frames (Red): 45 /30 Duration: 2 minutes Gain: 100
Number of light frames (Green): 71 Duration: 2 minutes Gain: 100
Number of light frames (Blue: 15 / 65 Duration: 2 minutes Gain: 100
Camera Temperature: 0 degrees C Binning: 1x1 F-Stop: 7.0
Total Integration Time: 10.37 hours
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Number of flat frames (LUM): 0 Duration: 0.027 Gain:100
Number of flat frames (Red): 0 Duration: 0.082 Gain: 100
Number of flat frames (Green): 0 Duration: 0.054 Gain: 100
Number of flat frames (Blue): 0 Duration: 0.12 Gain: 100
Flat Field Illumination: All-Pro 'Spike-a-Flat Field standard' illuminated panel
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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
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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 DynamicCrop, GraXpert, BlurXTerminator, NoiseXterminator
RED/GREEN/BLUE DynamicCrop, GraXpert, ChannelCombination to create color image using only Red/Green/Blue, ImageSolve, SpectroPhotometricColorCalibration, BlurXTerminator, NoiseXterminator
Non-Linear:
LUM: GeneralizedHyperbolicStretch script
COLOR: GeneralizedHyperbolicStretch script, GAME script to create mask of nebula, HistogramTransformation to darken background, MultiScaleLinear Transform to sharpen.
ImageBlend script to combine Lum and color images, HistogramTransformation to darken background, HDRMultiScaleTransform to increase contrast,
GAME script to create mask of nebula, HistogramTransformation to darken background, MultiScaleLinear Transform to sharpen, BlurXterminator to sharpen stars, DynamicCrop.
Notes:
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