NGC 891: unbarred spiral galaxy in the constellation Andromeda

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NGC 891 (also known as Caldwell 23) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus. The object is visible in small to moderate size telescopes as a faint elongated smear of light with a dust lane visible in larger apertures.
NGC 891 looks as we think the Milky Way would look like when viewed edge-on (some astronomers have even noted how similar to NGC 891 our galaxy looks as seen from the Southern Hemisphere) and in fact both galaxies are considered very similar in terms of luminosity and size; studies of the dynamics of its molecular hydrogen have also proven the likely presence of a centralbar. Despite this, recent high-resolution images of its dusty disk show unusual filamentary patterns. These patterns are extending into the halo of the galaxy, away from its galactic disk. Scientists presume that supernova explosions caused this interstellar dust to be thrown out of the galactic disk toward the halo.

Imaging telescopes or lenses: TPO 8″ Ritchey–Chrétien
Imaging cameras: SBIG ST-8300M
Mounts: Orion Atlas EQ-G
Guiding cameras: SBIG ST-i Planetary and Guide Camera Mono
Software: DeepSkyStacker, PHD guiding, photoshop, Nebulosity
Filters: Astrodon Tru-Balance Generation 2 E-Series – LRGB 36mm Round Fil
Accessories: SBIG OAG-8300
Dates: Nov. 28, 2013
Locations: Cedar Key, FL
Frames:
Astrodon Tru-Balance Generation 2 E-Series – LRGB 36mm Round Fil: 11×1200″ -20C bin 1×1
Astrodon Tru-Balance Generation 2 E-Series – LRGB 36mm Round Fil: 12×600″ -20C bin 2×2
Integration: 5.7 hours

Autor: Mike Carroll

08 March 2014

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