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The Sailboat Cluster

The Sailboat Cluster in Cassiopeia The Sailboat Cluster in Cassiopeia ©2016 Frederick Steiling

Featured in Astronomy Magazine: March 2017, Pg. 70

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Target Information
Main Target Designations NGC225, VdB4
Companion Objects LDN1291, LDN1294, LDN1300, Berkeley-3
RA Center 00h 43m 38.935s
DEC Center +61° 54' 19.45"
Rotation 0.256°
Pixel Scale 1.628 arcseconds/pixel
LRGB 580’/127.5'/120'/135'
L subframes 29x1200" @ 1x1
R/G/B subframes 17/16/18 x 450" @ 1x1
Total Integration 16hrs 2min 30sec
Date(s) of acquisition 04Sep2016, 05Sep2016, 10Sep2016, 24Sep2016, 26Sep2016, 27Sep2016
Locations Whiteside, MO
Imager SBIG STF-8300M
Telescope/Lens Orion 8" f/3.9 Astrograph
Mount Celestron CGEM (DIY Hypertuned)
Guiding Apparatus OAG-8300
Guiding Camera QHY5L-II
Filter Wheel FW5-8300
Wide Filters Astronomik LRGB
Narrow Filters Astronomik 12nm Hα
Coma Corrector Baader MPCC Mark III
Collimator Howie Glatter 650nm laser
Focusing Moonlite CR with V2 High-res Stepper
Acquisition Sequence Generator Pro
Guiding PHD2
Processing PixInsight 1.8

Twinkle, twinkle, thousands of stars!

With more than 100 billion stars in the Milky Way, you get an eyeful when imaging a slice of its arm, which is what we have here in this region near Navi, the center star of the Cassiopeia “W”.

Scattered throughout this rich star field are a number of very interesting structures, beginning with the Sailboat Cluster (NGC225).  Just south of center at a distance of 2100 light years, this young tub-shaped collection of stars compose one of the more identifiable open cluster resemblances we find in the Milky Way.  Caroline Herschel originally discovered and recorded this in 1783 as #11 on her list... then again as #15 in 1784.  Can't blame her for losing track in a busy region like this!

Rising behind the boat like a mast and sail is an interstellar cloud mass (VdB4) shining with reflected light, above which the dark overcast of the nebula LDN1291 looms large.  Near the top edge of the frame, LDN1294 sinks another dark hole in the image, while a sea of more diffuse dark clouds creeps in from the bottom-center of the frame (LDN1300).  A very small closely-knit open cluster identified as CA Berkeley-3 also makes its home toward the right-center edge of the image.

Open clusters are generally considered easier photographic targets because their structure is very bright compared to other deep space objects.  However in this frame, we have the incredible challenge of exposing the very dim cloud regions behind and around the cluster.  I’ve opted for long luminance exposures (20’) in an effort to grab enough cloud signal, but at the cost of increased star bloating.  This made processing a bit of a challenge in controlling the star size and brightness, but close attention resulted in a pretty pleasing result for a surprisingly difficult target.

Even areas of basic open clusters have the ability to reveal some unbelievable delicacies.  There simply is no boring part of the night sky!

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