⁣NGC 3576 - The Statue of Liberty Nebula

Last time around when I captured this nebula a year ago, my field of view was half the size it is now. This is the the widefield version showing some of the sprawling nebulosity that sits above this eerie figure. ⠀ An uncommon southern target, many people have never heard of it let alone seen it. Here it is imaged in SHO with 11.75 hours worth of integration time under a pretty bright moon.⁣ Thanks for looking! I hope you like it.

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Equipment:

Scope: William Optics GT81-II F/5.9 Triplet APO @ 382mm

FF/Reducer: WO Flat6A-iii

Mount: EQ6-R PRO

Imaging camera: ZWO ASI1600MM with matching ZWO 36mm filters and 7 slot filter wheel

Guiding: WO 50mm guide scope with a ZWO 290mm guide camera

Pixel scale 2.04 arc/s

Accessories:

DeepSkyDad Autofocuser

Dew control dew heaters

Software:

SGPro

PHD2

SharpCap for polar alignment

Integration details:

All frames at 200 gain 50 offset and cooled to -10c

Sii 86 * 180s

Ha: 96 * 180s

Oiii 53 * 180s⠀

Location: Wellington, New Zealand - Bortle 4 skies

Processing:

Astro Pixel Processor

Pre-processing:

Individual frames calibrated, analysed, registered and normalised.

Stacked in APP on Auto with drizzle applied (droplet 0.75, scale 1.5)

Pixinsight

Post processing:

Individual frames:

Cropped to remove stacking artifacts at the borders

Linear fit to Ha channel and Ha duplicated to use as a luminance channel

ABE on each channel

Jon Rista method of noise reduction (TGVD and MMT)

Channel combination to combine in SHO

SHO (RGB combined channel):

2 iterations of ArcsinhStretch to take non-linear

Background neutralisation

Auto histogram

SCNR

TVGDenoise

Lum:

2 iterations of ArcsinhStretch to take non-linear

Curves

TVGDenoise

Local histogram equalisation

MLT Sharpening

Unsharp mask

LRGB combined SHO:

Colour saturation

SCNR

Mulitple curves

Star reduction

MLT Sharpening

Exponential transform

Dark structure enhance script

More curves

Final stretch

Saved for further processing in Affinity Photo

Affinity Photo:

Saturation and vibrance

Cropped and re-sampled for web