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.
Date posted: July 1, 2007.
FSQ106 at f5 on the G11 Losmandy
Autoguider: SBIG ST-402 with
Camera: STL11K -20C.
Filter: Baader 7nm
Exposures: 6/23/07, 8 x 20';
6/27/07, 8 x 20'. Total exposure 5.3 hours.
Conditions: Temperature 70-80 degrees F, good
transparency, average seeing.
Calibrated, aligned, and Sigma Clip combined
in Maxim, followed
in ImagesPlus (IP). Further processing in Photoshop CS (16
note: Graphics on this website
may not be reproduced without author permission.
Back to Hydrogen Alpha