Perhaps the last great sport left to amateurs is hunting for supernovae. With comets discovered regularly now by robotic monster scopes which pick up the faintest of comets sometimes years before amateurs and their gear can detect them, at least supernova hunting is still a first - in - first - served affair; If you see it then it is yours and amateurs are still making a dent in the supernova discovery stats, which is not what is happening much any more over at the comet section.
Now regarding clearing the neighbourhood. If such a stellar calamity occurred in our neighbourhood what would be the effect for us here on Earth? The optimists hope that a star further away than 30 light years will not hurt us much but on the other hand the pessimists are sure that anything blowing up for 2000 light years around will hurt us plenty.
Fortunately therefore, the NGC 7123 supernova that has just cleared enough space to make any developer envious is about 50 million light years away, meaning that this unhappy star popped its clogs, and those of many of its neighbours, just when the dinosaurs were all but gone and our own lineal ancestors were snuffling about in the ferns and undergrowth.