|
Instrument |
12.5" RCOS @
~f/9 (2880 mm fl) at 1.28 arcsec/pixel. Shown at 2.54 and 1.36 arcsec/pixel. |
|
Mount |
Paramount ME |
|
Camera |
SBIG STL-11000 w/
FW8 filter wheel, AstroDon Gen-2 Filters |
|
Acquisition Data |
12/22/2014
to 12/26/2014 Chino Valley, AZ... with CCD Commander & CCDSoft,
AOL guided. |
|
Exposure |
|
RGB |
480 min. (16 x 10 min.
each) Bin 2x2 |
|
|
Software & Processing Notes |
-
CCDSoft, CCDStack,
PixInsight & Photoshop CS6.
-
No SDSS stars were
available for color balancing, so a standard image-train color
calibration was used, as determined by
eXcalibrator v4.30, and then adjusted for altitude
extinction.
-
CCDBand-Aid to repair
KAI-11000M vertical bars.
-
CCDStack to
calibrate and register the sub
exposures and create the RGB image..
-
PixInsight
processing includes gradient repair and non-linear stretching with HistogramTransformation.
-
PhotoShop for
the final touch up.
|
|
Comment |
NGC 457 or Caldwell 13
is an open star cluster in the constellation Cassiopeia. It was
discovered by William Herschel in 1787, and lies over 7,900 light
years away from the Sun. It has an estimated age of 21 million
years. The cluster is sometimes referred by amateur astronomers as
the Owl Cluster. Two bright stars, magnitude 5 Phi-1 Cassiopeiae and
magnitude 7 Phi-2 Cassiopeiae can be imagined as the eyes. The
cluster features a rich field of about 150 stars of magnitudes
12-15.
Source:
Wikipedia |
