M100 (NGC 4321) is a spiral galaxy in Coma Berenices (Berenice's Hair).  It's a  part of the Virgo cluster, and sits at 60 million light years distance. It shines at  magnitude of 9.3, and is 7 by 6 arc-minutes in size.

In the above image on the top left is 15th magnitude NGC4322, and on the bottom right is 17th magnitude IC783A. This image is a single 2x2 binned 20 minute exposures. Taken with the ST-8E and 12" LX200 at f/10 with a mag 9.74 guide star. The image has been CCDSharp'd and shrunk a bit for display. Taken at the ARGO site in central Oregon on March 30, 2000.