Deep Sky

Pinwheel Galaxy

The constellation Ursa Major holds this nearly face on spiral galaxy.  A diameter of over 170,000 light-years and approx 27 million-light years from here.   M101 has a magnitude of 7.9 and one I'm particulary happy with.  This image is 'only' 60 images stacked and I'm sure we will get this one again in the near future.

This latest image of M101 comes after the type 1a supernova.  The last image was before it so unfortunately, we don’t have it here.  The latest thoughts for 1a supernova occur when a white dwarf siphons material from a neighboring or companion star.  At some point, enough material gathers on the dwarf, that it starts fusing hydrogen into helium.  Before long a run away effect kicks in and the star explodes!  Such explosions can release enough energy it can outshine its host galaxy.  Astronomers use the brightness of the type 1a supernova for judging distance as the explosion are pretty consistent.    
50 images
20 second
23 Mar 12