|
|
|
Instrument |
Takahashi FSQ-106ED @
f/5.0 (530 mm F.L.) Captured at 2.1 arcsec/pixel. The Zoomify
image scale is 2.80 to 9.85 arcsec / pixel. |
|
Mount |
Losmandy G11 with Gemini L4 v1.0 |
|
Camera |
SBIG STF-8300M Self
Guiding Package w/ mono ST-i, using Baader filters. |
|
Acquisition Data |
9/25/2012 to 10/21/2012 Chino Valley, AZ... with CCDAutoPilot5
& CCDSoft. Off-axis guided. |
|
Exposure |
|
Red |
95 min. (19 x 5 min. bin 1x1) |
|
Green |
125 min. (25 x 5 min.
bin 1x1)
|
|
Blue |
170
min. (34 x 5 min. bin 1x1) |
|
|
Software |
-
CCDSoft, CCDStack,
Photoshop CS6 and Russell Croman's GradientXTerminator.
-
No SDSS stars were available for color balancing, so a standard image-train
color
calibration was used, as determined by
eXcalibrator v3.1, and then adjusted for altitude extinction.
-
CCDStack to calibrate,
register, normalize, data reject, sum-combine the sub exposures and RGB
image.
-
PhotoShop for
non-linear stretching.
|
|
Comment |
North is to the top.
The Double Cluster is
composed of NGC 884, on the left, and NGC 869 to the right. The
cluster, located in the constellation Perseus, is visible to the
naked eye. However, its true beauty becomes apparent when viewed
with binoculars or a small telescope. The Double Cluster is thought
to be about 7,000 light-years away, with NGC 869 a few hundred
closer.
The NGC 884 and 869 are surprisingly blue, considering how much
galactic dust is in our line of sight. The Solar System is in the
inner part of our galaxy's Orion arm and the cluster is in the next
outward arm. Looking through all this dust shifts the color toward
the red. However, the cluster's relative movement is toward the
Solar System. This makes the light blueshifted and offsets the
reddening a bit. |
|
