A supernova is a spectacular explosion of a massive star. If our sun exploded as a supernova, the resulting shock wave probably wouldn't incinerate the entire Earth, but the side of Earth facing the sun would boil away.

What would happen if a supernova hit Earth?

Both types are extremely powerful, sending energetic radiation and blast waves of ejected gas far into space. If a supernova explosion were to occur within about 25 light-years of Earth, our planet would probably lose its atmosphere, and all life would perish.

How long would it take for a supernova to destroy Earth?

Time it takes to vaporize the Earth is 7.8×1031 J2.55×1030 Js=30s.