What if a star explodes near Earth?

what would happen if a star exploded near the Earth well the nearest star to Earth of course is the sun and it is not going to explode but if it had eight times the mass then it would go supernova at the end of its life so what would that look like well as noted by xkcd if you held up a hydrogen bomb right to your eyeball and detonated it that explosion would still be a billion times less bright than watching the sun go supernova from Earth that's how insanely powerful Supernova explosions are they are the biggest explosions in the universe when we see Supernova in other galaxies they are brighter than the combined light of hundreds of billions of stars so bright in fact that they appear to come out of nowhere on the 8th of October 16004 the astronomer Johannes Kepler looked up into the night sky and noticed a bright star he had never seen before it was brighter than all the other stars in the sky and about as bright as the planet Jupiter on moonless nights it was bright enough to cast a shadow Kepler published his observations of this star in a book called Della Nova which means about a new star in Latin Kepler thought he was witnessing the birth of a new star but it was actually a Stars violent death over the following year and a half the light faded until it was no longer visible but the name stuck even once we learned what was really happening in the 1930s the violent final explosion for stars between about 8 and 30 solar masses has been called a supernova but how exactly a star explodes is not what most people think for most of a star's life it exists in a state balance in its core it fuses lighter elements together to make heavier ones and in the process it converts a small amount of matter into energy this energy is really what keeps the star from collapsing in on itself gravity compresses the star but that force is counteracted by the pressure generated by the movement of particles inside the star and by the pressure of photons released by Fusion so in effect stars are propped up by their own light if the rate of fusion drops at the center of the star the temperature and ...