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Click the image for a wider ~
75% size view. (2400 x 1600 - 1.18 MB)
"Mouse Over" view is LRGB only
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Instrument |
12.5" RCOS @
~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at 0.5 and 0.83 arcsec/pixel. |
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Mount |
Paramount ME |
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Camera |
SBIG STL-11000 w/
FW8 filter wheel, AstroDon Gen-2 LRGB & a 6nm Ha filter. |
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Acquisition Data |
11/20/2015 to
2/2/2016 Chino Valley, AZ. with CCD Commander & CCDSoft. AOL
guided |
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Exposure |
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Lum |
495 min (33 x
15 min) Bin 1x1 (best of 53) |
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RGB |
540 min (12 x
15 min. each channel) Bin 2x2 |
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Ha |
810 min (27 x
30 min. each channel) Bin 1x1 |
eXcalibrator RGB ratios are 1.00,
1.05 & 1.10 |
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Software & Processing Notes |
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CCDSoft, CCDStack,
PixInsight, Photoshop CS6.
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eXcalibrator
v5.0 for (g:r) color balancing, using
78 stars from the
APASS database.
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CCDBand-Aid to repair
KAI-11000M vertical bars.
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CCDStack to
calibrate all sub exposures and create the RGB image.
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PixInsight to
register, normalize, data reject, combine the luminance sub exposures,
gradient removal, non-linear stretching with HistogramTransformation and to create the LRGB image.
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PhotoShop for the final touch-up.
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Comment |
North is to the top.
The Crab Nebula, located 6,500 light-years away, is the result of a
star that was seen to explode in 1054 AD. This spectacular supernova
explosion was recorded by Chinese and (quite probably) Anasazi
Indian astronomers. The filaments are mysterious because they appear
to have less mass than expelled in the original supernova and higher
speed than expected from a free explosion. In the nebula's center
lies a pulsar: a neutron star rotating 30 times a second.
Source: NASA APOD
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