Magnitude 23..maybe a 40" scope might do the trick
I've been following progress on Pan-Starrs and I know it hasn't been smooth sailing for them as they have had quite a few technical issues with the scope and camera. On top of that there are 12 science teams competing for time with the scope. As an example only 5% of the survey's time is allocated to NEO searches, not sure what the breakdown is for supernova searches.
I'm sure once it gets going it will really be impressive.
Terry