|
Instrument |
12.5" RCOS @
~ f/9 (2880 mm fl) at 0.64 arcsec/pixel. Shown at 1.13 & 3.17 arcsec/pixel. |
|
Mount |
Paramount ME |
|
Camera |
SBIG STL-11000 w/
FW8 filter wheel & AstroDon Gen-2 LRGB filters. |
|
Acquisition Data |
11/16/2015 to
12/12/2015 Chino Valley, AZ. with CCD Commander & CCDSoft. AOL
guided |
|
Exposure |
|
Lum |
255 min (17 x
15 min. each) Bin 1x1 |
|
RGB |
405 min ( 9 x
15 min. each) Bin 2x2 |
eXcalibrator RGB ratios are 1.00,
0.87 & 0.91 |
|
Software & Processing Notes
|
-
CCDSoft, CCDStack,
PixInsight, Photoshop CS6.
-
eXcalibrator
v6.1 for (g:r),(b:r) color balancing, using
425 stars from the Pan-STARRS database.
-
CCDBand-Aid to repair
KAI-11000M vertical bars.
-
CCDStack to
calibrate the sub exposures.
-
PixInsight to
register, data reject, mean combine the sub exposures and
create the LRGB image. Also for
gradient removal, non-linear stretching with HistogramTransformation.
MorphologicalTransformation was used to make the brightest stars
appear smaller.
-
PhotoShop for
background noise reducetion.
-
Noiseware 5, a PhotoShop plug-in.
|
|
Comment
|
The north is to
the left.
NGC 225 is an open cluster NGC
about 2,000 light years away in the constellation Cassiopeia and was
discovered by Caroline Herschel in 1783. The cluster is very young with an estimated age of only one to 10
million years.
Nearby is the blue reflection nebula vdB 4. This may be the remains
of the nebula that formed the star cluster.
|
