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Instrument |
12.5" RCOS @
~f/9 (2880 mm fl) 0.643 arcsec / pixel. Zoomify image scale is
0.96 to 2.88 arcsec / pixel. |
|
Mount |
Paramount ME |
|
Camera |
SBIG STL-11000 w/ internal filter wheel, AstroDon 6nm Filter |
|
Acquisition Data |
11/01/2009 to
12/17/2009 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft. |
|
Exposure |
Hα 660 min
(22 x 30 min, bin 1x1)
|
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Software |
-
CCDSoft, CCDStack,
Photoshop CS w/ the Fits Liberator plugin and Noel Carboni's
PhotoShop actions.
-
PixFix32 (pre-beta) to
repair hot/cold pixels and column defects.
-
CCDStack to calibrate,
register, normalize, data reject, & combine the sub exposures.
-
PhotoShop for
on-linear stretching.
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Comment |
North is to the left.
At a distance of about 1500 light years, the Horsehead Nebula, in
Orionis, is part of a large dark molecular cloud. Also known as
Barnard 33, the unusual shape was first discovered on a photographic
plate in the late 1800's. The background glow originates from
hydrogen gas predominantly behind the nebula, ionized by the nearby
bright star Sigma Orionis. The darkness of the Horsehead is caused
mostly by thick dust, although the lower part of the Horsehead's
neck casts a shadow to the left.
Source: NASA APOD
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