So here it is - as seen by the Sloan Digital Sky Survey.
|M100 as seen by the Sloan Digital Sky Survey|
|The central region of M100 seen by the Hubble Space Telescope.|
M100 is a classic example of a grand design spiral, meaning it has clear well defined spiral arms. And look how far round they wind - it's lovely. Its classic classification (from the RC3 as listed in NED) is as an Sbc galaxy with a weak bar and an inner ring (SAB(s)bc). Apparently it's a similar size galaxy to our own Milky Way, and has played an important role in the history of extragalactic astronomy. This object is a member of our nearest large cluster of galaxies - the Virgo Cluster, and in 1994 was the first galaxy in the Virgo Cluster to have a distance measured to it using Cepheid Variables (via the Leavitt Law, see Freedman et al. 1994) which was an important step towards a reliable measurement of the Hubble constant.
Oh, and I should put in a plug for the excellent LookUP website, by @astronomyblog (Stuart Lowe). Check out the LookUP entry for M100 - turns out it also has a very interesting black hole - possibly the youngest known, and born in the same year as me. Cool!