SH2-171, NGC 7762, King 11 (Hydrogen Alpha)

Found a rather offbeat target that was fun to capture. Sharpless 171 is of course a nebula, and a rather large one. NGC 7762 is an open cluster near the bottom center, while King 11 is above it and to the right. The photos below represent about 1/6 of the total size of SH2-171!

The nebula is also known as the cosmic question mark.

The first phase was capturing Ha.

Scope	Explore Scientific FCD100 ED127 Triplet Refractor
Mount	Losmandy G811G
Reducer	Apex .65 Starizona
Flattener	-
Camera	ZWO ASI 294MM
Filters	Antlia Ha 3.5nm	Antlia 3.5nm SII	Antlia 3.5nm OIII
Software	NINA 2.0	PHD2	PixInsight
Bortle	~7.5
Capture Eq.	Beelink SEi8 Mini PC	Pegasus Pocket PB
Guide Scope	Agena 60mm
Guide Camera	Zwo ASI120MM-S

Date(s)

Bin

Gain

Cam Temp

Filter

# Exps

Length

Hrs

Throw Away

Moon Phase

Seeing

Transp

8/9/2022

2x2

120

-10

Ha

40

180

2.0

0

>95%

4

5

Stars Removed

PixInsight Processing

Linear Processing

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Dyanmic Crop to remove bad edges

Automatic Background Extraction

NoiseExterminator AI to remove noise

EZSoftStretch script to bring to Non-Linear state (Target Median = .25)

Non Linear Processing 

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StartXterminator to remove stars

HDRMultiscaleTransform to bring out contrast (7 layers)

Curves - a couple of slight S-curve to slightly darken background and lighten nebula

LocalHistogramEqualization - Kernel Radius = 25 to bring out some contrast

LocalHistogramEqualization - Kernel Radius = 75 to bring out more contrast

LocalHistogramEqualization - Kernel Radius = 125 to bring out more contrast

MultiscaleLinearTransform to sharpen

Added stars back in with PixelMath

NoiseExterminator AI to remove noise