Galaxy NGC 891 in Andromeda
When viewed from the side (called "edge-on" by astronomers), the spiral galaxies can be observed as relatively thin discs.  The example here
NGC 891, an edge-on spiral galaxy in Andromeda, with estimates of its distance varying from 24-32 million light years away.  The dark
lane bisecting the galaxy is a huge band of dust encircling the disc of the galaxy, blocking out the central band of stars.  I have imaged
another edge-on galaxy,
NGC4565, from my backyard.

For those of you who remember the TV show "Outer Limits", you may recall this galaxy shown in the opening credits.  For this reason,
NGC 891 is often called the Outer Limits Galaxy.

This image combined 120 minutes Luminance (unbinned) through a clear filter with 60 minutes each through red and blue filters, and 75
minutes through a green filter (binned 2x2).  I used an ST10-XME camera through a Meade 12" LX200R with an Astro-physics 0.67x
reducer, taken at the Hidden Valley Observatory.
Music:  Nights in White Satin by the Moody Blues