NGC 891 is one of the most striking examples of a spiral galaxy seen exactly edge-on. This ghostly spindle of light is located about midway between Gamma Andromedae and the open star cluster M34 in Perseus.
Although NGC 891 is a generous 14′ by 3′, it suffers from low surface brightness. On nights with poor seeing, NGC 891 is a wavering apparition suspended in a bowl of glittering stars. However, if your sky is dark and steady the big galaxy takes magnification surprisingly well.
NGC 891’s signature feature is a prominent equatorial dust lane. The dark band clearly bisects the galaxy in 8-inch telescopes at 150x. Using averted vision note the mottled extensions of the galaxy, and even a central bulge of sorts.
NGC 891 has an optical diameter of about one hundred thousand light years and the dust lane has a width of about 1.5 thousand light years. Professional telescopic studies indicate that the galaxy is not perfectly edge-on, but instead the eastern side is inclined just slightly toward us and the western side just slightly away from us (the rotation axis is inclined at an angle of 89° from our line-of-sight; 90° would be exactly edge-on).
Finder map – field width 15°, stars to magnitude +8.