Not to mention the fact that our sun won't go supernova. It doesn't have enough mass to do so. It will expand into a red giant, likely engulf the Earth (not garentteed, though, but even if it doesn't, the Earth will still be uninhabitable) then slowly cool and shrink into a white dwarf.
And *then*, after it exhausts its supply of heavy elements, it will go nova. Nova and supernova are simmilar in nature, only supernova makes a bigger bang and requires a more massive star.
As for your army of sentient machines, my army of Jedi will make short work out of them. Just look how the robots got licked in Star Wars!
Sentient machines are so cliche, why not force evil dolphins to evolve legs and kill us all...
With lazer beams attached to their heads?