The Double Cluster (NGC 869 and NGC 884)
Characteristics:
Magnitude: 6.1
Size: About 30' each cluster
Distance: 7100 light years for NGC 869; 7400 light years for NGC 884
RA: 02h 22m 32s
Dec: 57 degrees 08' 38"
Description:
The famous Double Cluster in Perseus
was first cataloged by the Greek astronomer Hipparcos in 130 BC.
These beautiful, young open clusters are filled with hot blue stars and
are separated by only a few hundred light years from each other.
More information about the Double Cluster may be found here.
Photographic Details:
Date: November 6, 2004
Scope: Takahashi
Sky 90 at f4.5 with field flattener/focal reducer, on the G11 Losmandy
Mount. I made a circular rim out of PVC tubing which fitted over
the dew shield of the Sky90 and permitted placement of an elastic band
to form an "X". This created the star spikes shown above for the
brighter stars. A photograph of this device is shown here (this
could also
be accomplished with kite string or fishing line).
Autoguider: SBIG STV with
e-finder.
Camera: SXV-H9
Filter: Astronomik
Type II R, G, B, plus clear filter set.
Exposures: L:R:G:B. 8 x 2'
for Luminance (clear filter), R, G, and B (16 minutes total
for each filter), all unbinned.
Conditions: Temperature 40 degrees F; average
transparency; below average seeing; a bit breezy; occasional high, thin
clouds passing through.
Post-processing: No darks,
flats, or bias frames used. Alignment done in ImagesPlus.
Sigma
combined using RC Sigma Reject Plug-in for MaximDL. DDP was
performed in ImagesPlus
(IP). Lucy-Richardson
deconvolution of the luminance layer was performed in IP and was
superior to simple unsharp masking for this image. Subsequent
levels and curves adjustments in Photoshop CS (16 bit format).
Please
note: Graphics on this website
may not be reproduced without author permission.
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