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5
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Click the image for a ~ 75% size view. (1500 x
1000 - 1.06 MB)
Click here for 150% crop of M9 (1200 x 800 - 0.89 MB)
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Instrument |
12.5" RCOS @ ~
f/9 (2880 mm fl) at 1.28 arcsec/pixel. Shown at 0.85, 1.71
and 3.42 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 filters. |
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Acquisition Data |
6/19/2018 to 8/7/2018 Chino Valley, AZ. with CCD Commander & CCDSoft. AOL
guided |
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Exposure |
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RGB |
720 min (16 x
15 min. each) Bin 2x2 |
eXcalibrator RGB ratios are 1.00,
1.13 & 1.24 |
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Software & Processing Notes |
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CCDSoft, CCDStack,
PixInsight, Photoshop CS6.
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eXcalibrator
v6.1 for (g:r),(b:r) color balancing, using
262 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 the sub exposures.
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PixInsight to
register, data reject, mean combine the sub exposures and
create the RGB image. Also for
gradient removal, non-linear stretching with HistogramTransformation
and color saturation.
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PhotoShop for selective
sharpening and JPEG creation.
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Comment
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The north is ~ to top,
the view is rotated 15° clockwise.
Messier 9 or M9 (also
designated NGC 6333) is a globular cluster in the constellation of
Ophiuchus at a distance of about 26,000 light years. Charles Messier
discovered the cluster on June 3, 1764. M9 is passing through an
interstellar dust cloud that dims and slightly reddens it's light.
Below and to the right is the more distant dark nebula, Barnard 64.
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