Celestial hemisphere:  Northern  ·  Constellation: Gemini (Gem)  ·  Contains:  IC 443  ·  IC 444  ·  Part of the constellation Gemini (Gem)  ·  The star Propus (ηGem)  ·  The star μGem
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The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha, Andrew Klinger
The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha
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The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha

Getting plate-solving status, please wait...
The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha, Andrew Klinger
The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha
Powered byPixInsight

The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha

Equipment

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Acquisition details

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Description

Equipment:

OTA: William Optics GT81 w/0.8x reducer (382mm fl at f/4.7)

Mount: Orion Sirius EQ-G (HEQ-5)

Guidescope: Orion 50mm guidescope

Guiding camera: Orion StarShoot Autoguider

Imaging camera: ZWO ASI1600MM-Cool

Software:

SGP

PHD2

CdC

PixInsight

Acquisition:

Location: Flower Mound, TX (Bortle 7)

Dates: 12/9/17, 12/10/17, 12/11/17, 12/20/17

Gain: 200 Offset: 50

Camera temp: -20C

Ha: 283x300" Astrodon 5nm

Total integration time: 23hr 35min

64x darks per calibration (master from library)

30x flats per calibration

200x bias per calibration (master from library)

Preprocessing:

Batch PreProcessing script to generate calibrated images

StarAlignment

LocalNormalization

ImageIntegration (Linear Fit rejection)

DrizzleIntegration

DynamicCrop

DBE

Processing:

Deconvolution

TGV & MMT noise reduction (via Jon Rista's method)

HistogramTransformation x2

Duplicated the image to create a starless version, using a starmask and several iterations of MMT and MT. Then pushed the faint nebulosity in the starless version using PixelMath expression: "1-(1-$T)*(1-$T)"

Combined the starless version with the image using PixelMath expression "F=0.2; (1-(1-$T)*(1-s)*F)+($T*~F)" (s=starless photo).

LocalHistogramEqualization

MLT for sharpening

MMT for slight noise reduction

HistogramTransformation to move black point in

CurvesTransformation for contrast

MorphologicalTransformation for slight star reduction

ACDNR for slight noise reduction

Resampled to 50% for web posting

Comments

Sky plot

Sky plot

Histogram

The Jellyfish Nebula (IC443) imaged in Hydrogen-alpha, Andrew Klinger