NGC 7635. The Bubble Nebula.

Note
My first image of a nebula. Cropped from a widefield image, and rather hard processed in CS2. Perhaps I have overdone the saturation a bit.


About
NGC 7635, also called the Bubble Nebula and Sharpless 162, is a H II region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, the 15 ± 5 M☉ SAO 20575 (BD+60 2522).

The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by Friedrich Wilhelm Herschel. The star SAO 20575 or BD+602522 is thought to have a mass of 10-40 Solar masses.

With an 8 or 10-inch (250 mm) telescope, the nebula is visible as an extremely faint and large shell around the star. The nearby 7th magnitude star on the west hinders observation, but one can view the nebula using averted vision. Using a 16 to 18-inch (460 mm) scope, one can see that the faint nebula is irregular, being elongated in the north south direction.



Processing
Maxim DL, CS2 and Noise Ninja.

Exposure
16 x 200 sec.

Calibration
Darks, bias and flats.

Filters
N/A

Cooling temp
-25´ C

Mean FWHM
3.11"

Date
September 28th 2010

Location
Krigslida, Stockholm, Sweden.
N59 06 52.4    E 18 03 54.5

Image aqusition
MaximDL Pro

Scope control
Sky X Pro Native drv, and Maxim DL with Astro-Physics V2 drv.

Telescope
WO FLT 110 DDG

Mount
Astro-Physics Mach 1 GTO

Camera
SBIG ST-8300C

Guiding
ZS 70 Doublet + QCam 5 Guider

Focus system
Lakeside motorfocus.


Inverted B/W image