Supernoves

Stars dont live for ever, but they lives for a long time.Some stars when they die the supernova occurs. It is a giant explotion that killes everything around it.

The nearast star to us is Alpha Centauri and it is 4.3 light years away. If it exploded would we have 4.3 years beofore we died? No, we woudn't. We would die at the same time.
A supernova will occur once every 200-300 years in each galaxie.