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The Deer Lick Group & Stephan's Quintet

The Deer Lick Group & Stephan's Quintet in Pegasus The Deer Lick Group & Stephan's Quintet in Pegasus ©2015 Frederick Steiling
Target Information
Main Target Designations NGC7331/C30, NGC7317, NGC7318, NGC7319, NGC7320
RA Center 22h 36m 59.515s
DEC Center +34° 13' 55.01"
Rotation 90.755°
Additional Images
Published image Full resolution
Annotated image Pop up preview
Full resolution
Exposures
LRGB 460’/180'/185'/190'
L subframes 1200" @ 1x1
R/G/B subframes 600" @ 1x1
300" @ 2x2
Total Integration 16hrs 55min
Date(s) of acquisition 13Sep2015, 15Sep2015, 16Sep2015, 14Oct2015
Locations Whiteside, MO
Equipment
Imager SBIG STF-8300M
Telescope/Lens Orion 8" f/3.9 Astrograph
Mount Celestron CGEM
Guiding Apparatus OAG-8300
Guiding Camera QHY5L-II
Filter Wheel FW5-8300
Wide Filters Astronomik LRGB
Narrow Filters Astronomik 12nm Hα
Accessories
Coma Corrector Baader MPCC Mark III
Collimator Orion LaserMate
Focusing Bahtinov mask
Software
Acquisition Sequence Generator Pro
Guiding PHD2
Processing PixInsight 1.8

This image presentation was last processed on 2017Feb11
The original version can be found here.


In a double display of cosmic playfulness, here we see one of the busier galactic areas in our sky, complete with a psuedo-Milky-Way twin and an interacting 4-galaxy group with an impostor.

On the right of the frame, the dominant NGC7331 shows its spiral form splendidly at a distance from us of about 45 million light years.  The frisbee-like inclination of the disc graces us with a deep look at one of the competing forms to which some liken our own Milky Way.  The main galaxy of the "Deer Lick" group, NGC7331 appears to show a humorous spattering of galactic "fleas" hopping off of it.  These spiral creatures are small only due to added distance, coming in at roughly 10 times the distance of their largest apparent neighbor, a staggering 400-500 million light years away.  Their flea-like appearance, however, has no correlation to the animal-based name of the group, but rather draws its brand from the location amateur astronomer Tomm Lorenzin experienced a magnificent view of it, the Deer Lick Gap in North Carolina.

Not to be outdone by the larger group in the same field of view, Stephan's quintet (to the bottom-left of the image) is consumed by some antics of its own, as well as some earthly historic significance.  These 5 galaxies, first discovered by Édouard Stephan in 1877, represent the first small galaxy cluster ever identified.  4 of these galaxies are very interactive, perhaps most evidenced with a recent discovery of a Milky-Way-sized shock wave produced from the collision of NGC7318B (the bottom of the quintet's "triplet") with the rest of the group.  The quintet, though, isn't quite as the name would indicate.  NGC7320, the bluish galaxy to the left of the quintet, has retained its shape for a good reason -- it sits quite a bit closer to us than the rest of the group, and only through its line-of-sight to us does it appear to be alongside the rest.

The fun doesn't end there!  Another vestige of a treat sits throughout the entire frame in the form of "splotchiness" and represents one of the greatest achievements in my image data yet.  This cloudy variability isn't a result of clouds in our own atmosphere... It's the result of clouds in our galactic atmosphere!  Coined as the Integrated Flux Nebula (IFN), this very thin collection of dust particles, hydrogen, and carbon monoxide are illuminated by the flux generated by all the stars in the Milky Way (rather than being illuminated through localized reflection or energization, as is the case with nebulae seen throughout our galactic plane).  These dim, cirrus variances are present only at higher galactic altitudes (toward the north celestial pole) and are known to photobomb deeper images of targets in this area, much like what is seen here.

This image presented some new time-constraint challenges in my data acquisition.  After needing to toss quite a few 10' RGB subframes due to unexpected equipment problems, the quickly-setting galaxy groups needed a quick-acquisition solution.  I went with 5' 2x2 binned frames in order to gather all the color data in a single clear night with clouds forecast in the foreseeable future.  As a result, the color is a bit weaker than I'd like, but it allowed me to cut my losses and complete the image, something I'm very happy about, particularly with all of the wonderful mischief this frame has to offer us.

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