Tuesday, February 7, 2012

Pressure waves and galaxies

  In the southern part of the Coma Berenices constellation lies one of the brightest galaxies in of the Virgo-Coma cluster of galaxies, 55 million light years away. One of the first spirals to be discovered and being the site for 5 observed supernovae, this galaxy is nothing close to boring and quiet.

Messier 100

    Only half of that distance away (21 million light years), M 101 is a giant spiral galaxy measuring 170 000 light years across going through an intense episode of star formation, as seen from the many red spots (ionized Hydrogen) in the image, probably due to an encounter with another galaxy not too many millions of years ago. M 101 was also the site of the last supernova I've seen, SN 2011fe, the youngest type Ia to be discovered. 

Messier 101

Pressure waves, transient structures, gravitationally aligned orbits, ISM shocks = spirals! (some say...)

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