Beautiful Galaxy M100

I stumbled across a picture of the galaxy Messier 100 (NGC 4321) this morning, and just felt inspired to share it's beauty. I might share more of these as a way for me to learn the NGC numbers of some classic galaxy examples!

 So here it is - as seen by the Sloan Digital Sky Survey.

M100 as seen by the Sloan Digital Sky Survey
The central region has been observed by HST, which is also worth a look.

The central region of M100 seen by the Hubble Space Telescope.
And I encourage you to do a Google Image Search on Messier 100 to see the vast array of beautiful images of this galaxy (PS. avoid searching on M100 if you're squeamish. Yuck!).

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! 

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