Would a Federation warship like the Defiant out gun a Star Wars Star Destroyer? Who has a bigger armada? Who has the tactical advantage? Don’t forget that The Federation includes the Klingons, who love warfare and have fast, agile, heavily armed ships, with cloaking devices, and the Vulcans with superior logic and tactical planning.
Depends what type of supernova you’re talking about. Type Ia supernova are caused by runaway fusion but most supernova are caused by core collapse which is when the fusion in the core dies out and gravity wins causing the star to explode. Depending on the size of the star you might even get a black hole at the end of this explosion.