The Crescent Nebula (NGC 6888)
Size: about 20'
Distance: 4,700 light years
RA: 20h 12m 48s
Dec: 38 degrees 19' 00"
The Crescent Nebula is not a typical supernova remnant
like the Veil. It is probably a result of the slow
release of large amounts of gas from the dying central star seen in the
above photograph, known as Wolf-Rayet 136, which has not yet gone
supernova. The stellar winds
resulting from the release of this star's outer envelope compress and
excite surrounding hydrogen gas, resulting in Ha emission and the
characteristic layered texture to NGC 6888. More information
about this interesting region of space can be found here.
This represents the first light image for my new camera, the MaxCam
CM10 by Finger Lakes Instruments.
Date: June 4,
FS-102 at f6 with TOA-130 focal reducer, on the G11 Losmandy
Autoguider: SBIG STV with
Filters: Astrodon 6nm
bandpass Ha filter. R, G, B Astronomik filters.
Exposures: 15 x 8' each Ha; 4 x
4' each R, G, B. Total
exposure duration 168 minutes.
Conditions: Temperature 80 degrees F; below average
transparency; humid; poor seeing; slight breeze. Imaging
performed at -25 degrees C throughout (delta approximately 50 degrees
subs were debloomed with Ron Wodaski's Debloomer software, and then
aligned in Registar. Sigma combined using RC Sigma Reject
MaximDL, followed by DDP
in ImagesPlus (IP). Subsequent
levels and curves adjustments in Photoshop CS (16 bit format).
note: Graphics on this website
may not be reproduced without author permission.
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