Celestial hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)  ·  Contains:  Crescent nebula  ·  IC 4996  ·  NGC 6881  ·  NGC 6888  ·  PK074+02.1  ·  PK076+01.2  ·  Sh2-105
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NGC 6888, Scott Stirling
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NGC 6888

Getting plate-solving status, please wait...
NGC 6888, Scott Stirling
Powered byPixInsight

NGC 6888

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Description

Image data: 7/23/2018 - 8/19/2018

R = 12x 300s

G = 26x 300s

B = 12x 300s

H = 23x 1200s

O = 20x 1200s

PixInsight Processing steps:

- MureDenoise H, S, O

- AutomaticBackgroundExtractor R, G, B, H, S, O

- ChannelCombination RGB

- BackgroundNeutralization and ColorCalibration of RGB

- NBRGBCombination RGB w/HOO

- PixelMath H + S + O = synthetic Luminance

- DynamicPSF and export PSF image from ~70 selected stars

- Deconvolution using External PSF, 12 iterations, 0.0060 Global dark deringing and 2 layers of wavelet regularization at default settings.

- UnsharpMask on synthetic L (still linear) StdDev 0.70, Amount 0.80, Deringing 0.05

- ScreenTransferFunction --> Histogram stretch RGBHOO and L

- GREYCStoration with Amplitude 25 and Precision 0.7 on synthetic L

- LRGBCombination synthetic L --> RGBHOO

- CurvesTransformation and ColorMask to tweak saturation and highlights (many revisions and variations, noticing that the red Ha background brings out the teal halo around the crescent nebula if the red is allowed to saturate more around and behind it)

- export to png, crop ugly pixels on right side and top edges in MS Photos editor, upload to astrobin

NOTE: there is a small planetary nebula in this field of view, faintly visible in the lower left, northeast of IC4996. I thought it was a lens flare at first, but I think it's a small bubble nebula. Follow up: turns out that is known as the "Soap Bubble Nebula" and was discovered by an amateur in 2007: https://en.wikipedia.org/wiki/Soap_Bubble_Nebula. I’ve noticed the little bubble s much more distinct when the red Ha is desaturated behind / around its circumference.

Comments

Revisions

  • NGC 6888, Scott Stirling
    Original
  • NGC 6888, Scott Stirling
    F
  • Final
    NGC 6888, Scott Stirling
    G

G

Description: crop and hue adjust

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NGC 6888, Scott Stirling