NGC 891 - Silver Sliver Galaxy
NGC 891 is one of the most beautiful galaxies in the northern sky. It is located about 30 million light years away in the constellation Andromeda
and belongs to the "NGC 1023- Group", which can be thought of as similar to our "Local Group".
With a diameter of 150,000 light-years NGC 891 is one of the largest spiral galaxies in the sky and thus even a bit larger than our Milky Way, which
has a diameter of 120,000 light-years. But also from the morphology both galaxies are very similar. We look at NGC 891 directly from the side
(EdgeOn). Therefore the extent is 11.7'x1.6', which corresponds to an axial ratio of 7.3:1. Because of this special position, we have a great view of
the dust lane that divides the galaxy into two halfs. It shows some features, for example that in high resolution images fine dust filamants can be seen,
which are pushed towards the galaxy halo either by supernova explosions or stellar winds.
So far only one supernova has been observed in NGC 891, namely "SN 1986J" with a brightness of 14mag.
At a distance of 250,000 light years the "Silver Sliver Galaxy" has a small companion galaxy named UGC 1807.
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The galaxy is a stunning sight under a dark sky in a large 20" telescope. The surface brightness is quite low, so NGC 891 appears like a long, pale streak
at a magnification of 200x. The many brighter stars in the vicinity give the impression that the galaxy is floating in space. Simply fantastic!!!
The dust lane can be traced along almost its entire length and appears to be thicker at the center. At a magnification of 270x, you get the impression that
the edges appear slightly ragged, but this is difficult to grasp.
In close proximity to NGC 891 there are two tiny galaxies, but I could not find a name for them in SIMBAD. At 270x they are hard to see with indirect
vision, but cannot be held steadily. They flash out of the sky background every now and then for a short moment and then disappear again into the darkness.
