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Click the image for a ~ 70%
size view. (2000 x 1333 - 1.29 MB)
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Instrument |
12.5" RCOS @
~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at 0.93 & 2.47 arcsec/pixel. |
|
Mount |
Paramount ME |
|
Camera |
SBIG STL-11000 w/
FW8 filter wheel & AstroDon Gen-2 6nm Ha, 3nm OIII and LRGB filters. |
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Acquisition Data |
9/6/2018 to 10/10/2018 Chino Valley, AZ. with CCD Commander & CCDSoft. AOL
guided |
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Exposure |
|
Lum |
375 min (25 x
15 min. each) Bin 1x1 |
|
RGB |
405 min ( 9 x
15 min. each) Bin 2x2 |
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Ha |
1020 min (34 x
30 min. each) Bin 1x1 |
|
OIII |
540 min (18 x
30 min. each) Bin 1x1 |
eXcalibrator RGB
ratios are 1.00, 0.92 & 1.14 |
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Software & Processing Notes
|
-
CCDSoft, CCDStack,
PixInsight, Photoshop CS6.
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eXcalibrator
v6.2 for (g:r),(b:r)
color balancing, using 2093 stars from the Pan-STARRS database.
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CCDBand-Aid to repair
KAI-11000M vertical bars.
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CCDStack to
calibrate all sub exposures.
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PixInsight to
register, data reject, mean combine all the sub-exposures, create the LRGB
image,
gradient removal and non-linear stretching with HistogramTransformation .
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PhotoShop to add
the Ha and OIII data to the LRGB image,
additional background neutralization and background smoothing.
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Noiseware 5, a PhotoShop plug-in.
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Comment
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North is to the top.
Messier 27 (M27) is
excellent example of a gaseous emission nebula created as a sun-like
star runs out of nuclear fuel in its core. The nebula forms as the
star's outer layers are expelled into space. Known by the popular
name of the "Dumbbell Nebula", this beautiful interstellar gas cloud
is about 1,200 light-years away in the constellation Vulpecula.
Hydrogen alpha
filtered data were added to the red channel and OIII data were added
to the green and blue channels to show the extent of the outer halo. |
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