Well done and very accurate sketch--comparing it to the images in the links Carlos provided demonstrates how accurate you are with your star placement.
Those images also give you an opportunity to recalibrate your cardinal directions. North would be at the top and celestial west on the right in your sketch.
...I'm somewhat surprised that supernovae that brighten to magnitudes brighter than ~13.5 seem to occur so often. This would be my second in the past few months, the last being SN2011B. Just how often do these usually occur?
SN2011by is the brightest supernova so far this year, but 86 supernovae of varying brightness have been reported to the IAU since the beginning of 2011. Apparently, stars blow up all the time. http://www.cbat.eps....Supernovae.html