The Bubble Nebula in Hydrogen Alpha (NGC 7635)

Bubble Nebula in Hydrogen Alpha
All Images Copyright Steve Cannistra

Please click here for a medium-sized image (65%).
Please click here for a wide field view of this region.


Characteristics:
Magnitude:  about 7.0
Size: about 15'
Distance: 11,000 light years
Position Angle:  minus 87 degrees (Pinpoint)
RA (J2000): 23h 20m 41s
Dec (J2000): 61 degrees 10' 50"

Description:
The Bubble Nebula is one of only a few "bubbles" identified in the night sky.  It is an unusual nebula named for the surrounding bubble that is seen in the upper right portion of the photograph above, caused by gas ejected from a massive central star.  The rate of ejected gas is so brisk that it "runs into" the wall of the surrounding nebula, thus creating a boundary of higher density gas that forms the outer shell of the bubble.  More information about this process may be found here.

Photographic Details:
Date:  August 21, 2008
Scope:  Vixen VC200L at f9 (FL = 1800 mm) on the Takahashi NJP Mount
Autoguider:  SBIG ST-402 with 60mm guidescope, focal length 227mm
Camera:  Apogee U32 -20C
Filters: 
Astronomik 6nm Ha filter
Exposures:  13 x 20' (unbinned); Total exposure, 4.3 hours
Conditions:  Transparency good; FWHM approximately 2.4"
Post-processing:  Debloomed, calibrated, aligned, and Sigma Clip combined in Maxim.  DDP in ImagesPlus (IP).  Deconvolution in Maxim using Bob Vanderbei's Fat Tail Deconvolution script (3 iterations).  Further processing in Photoshop CS (16 bit format).


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