C27 The Crescent Nebula (Steve Argereow)

C27 The Crescent Nebula

NGC 6888 - C27-The Crescent Nebula

NGC 6888 - C27-The Crescent Nebula - is a faint emission nebula in Cygnus shining at magnitude +7.4. The Crescent Nebula, is a about 25 light-years across, blown by winds from its central, bright, massive star. Oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. Visible within the nebula, NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 was discovered by William Herschel on December 15, 1792, and is best seen from northern latitudes during the months of July, August and September. It's object 27 in the Caldwell catalogue. Distance 5,000 light years, and an apparent diameter of 18 X 12 arc minutes.

Information Credit: Home Free Star Charts/NASA Science

Telescope: Explorer Scientific 127mm CF - APO Refractor - f/7.5
Explorer Scientific Flatter/Reducer X0.7 Focal Length (667mm)
Mount IOptron CEM40
Camera ZWOASI6200MC

94 X 180 Second Exposures Optolong L-Extreme Gain 100 Offset 50
23 X 180 Second Exposures Astrodon OIII (3nm) Gain 100 Offset 50
Total Exposure Time 5 Hours 51 Minutes Taken 7/28 - 8/03 2021

Acquisition with SharpCap
Stacked with Astro Pixel Processor
Guiding PHD2
Processed with Astra Image/GIMP

Photo taken from Seven Lakes, NC Bortle 4.5

Original
Final
B

B

Description: The first image was a little too dark, so I increased midtones.

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Status	Advanced success
Started	...
Astrometry.net job	6131651
PixInsight job	TTNK0VURDJ69W2TBZJEC9ZUGB0W0TRSD
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	20h12m15s.37
RA (top/left)	20h10m05s.47
RA (top/right)	20h10m08s.78
RA (bottom/right)	20h14m22s.83
RA (bottom/left)	20h14m24s.17

Dec (center)	+38°21′22″.2
Dec (top/left)	+38°59′30″.4
Dec (top/right)	+37°42′53″.7
Dec (bottom/right)	+37°43′03″.1
Dec (bottom/left)	+38°59′39″.8

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