Supernova 2011dh.
Combination of 5, 3 minute images unfiltered.
SBIG STL-1001E CCD. 20" f/6.8 Dall-Kirkham cassegrain telescope at prime focus.
A bright supernova appeared in M51 at the beginning of June, 2011. At its brightest on about June 22, it reached around magnitude 12.4 and was easily visible in an 8" telescope.
I was able to image the supernova until July 2012, after which it became lost in the spiral arms of the galaxy. The resulting lightcurve is shown below. This supernova was a Type II, the spectacular death of a high-mass star.
Below is an animation of all of the imges I was able to obtain. It is possible to see the supernova brighten a little before fading away to nothing.
