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Contains:  NGC 6165, NGC 6188, NGC 6193, Rim Nebula
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NGC 6188 - The Fighting Dragons of Ara

Technical card


Dates:May 11, 2020May 17, 2020May 19, 2020

Frames:
ZWO Ha 36mm 7nm: 172x180" (gain: 139.00) -15C
ZWO OIII 36mm 7nm: 151x180" (gain: 139.00) -15C
ZWO SII 36mm 7nm: 151x180" (gain: 139.00) -15C

Integration: 23.7 hours

Avg. Moon age: 23.50 days

Avg. Moon phase: 37.59%

Bortle Dark-Sky Scale: 4.00


Basic astrometry details

Astrometry.net job: 3541672

RA center: 16h 38' 57"

DEC center: -48° 26' 31"

Pixel scale: 1.358 arcsec/pixel

Orientation: 305.720 degrees

Field radius: 1.219 degrees


Resolution: 5000x4092

Data source: Backyard

Description

This is a 23.7 hour SHO image of NGC 6188 - a popular southern hemisphere target known as the Fighting Dragons of Ara. This nebula resides within the open cluster called NGC 6193, which is invisible to the naked eye and responsible for lighting up the contours of this amazing scene.

Equipment:

Scope: William Optics GT81-II F/5.9, DeepSkyDad Autofocuser

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

Integration details:

All frames at 139 gain 50 offset and cooled to -15c

151x180s OIII (7.55h)

151x180s SII (7.55h)

172x180s Ha (8.6h)

Total integration time: 23.7 hours

Location: Wellington, New Zealand - Bortle 4 skies.

Processing:

Astro Pixel Processor

Individual frames calibrated, analysed, registered and normalised.

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

Pixinsight

Frames cropped to remove stacking artifacts at the borders.

ABE on each channel.

Jon Rista method of noise reduction (TGVD and MMT).

Ha was duplicated for use as luminance and then had deconvolution applied.

The luminance then had a starless copy created using StarNet and then had an s-curve, LHE and sharpening applied (potected with a starmask).

This was then combined with the non-starless image at 60%/40%.

SII, Ha and OIII frames taken non linear with ArcsinhStretch and HT and then channel combinted in SHO.

SHO (RGB combined channel):

CorrectMagentaStars script (inverts, SCNR, invert back).

SCNR @ 90%.

Small pass of ABE for lingering gradients.

TVGDenoise.

Mulitple curves transformations inlcuding hue shift to turn a nasty dull mustard into more of a copper red.

Star reduction following David Ault's excellent tutorial http://trappedphotons.com/blog/?p=731

LRGB comnination with Luminance.

LRGB combined SHO:

RGB/k and saturation curves.

Star reduction.

MLT Sharpening.

Dark structure enhance script.

Very conservative pass of DBE to remove a dominant blue gloss.

Further star reduction.

TVGDenoise to clear up the chromonance background structure.

More curves.

Saved for further processing in Affinity Photo.

Affinity Photo:

Adjsutments to levels, saturation, vibrance, contrast and selective colour.

Re-sampled for web.

Thanks for looking!

Comments

Author

mos_astro
mos_astro
License: None (All rights reserved)
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NGC 6188 - The Fighting Dragons of Ara, 



    
        

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