A star's lifespan and eventual death are determined almost entirely by its initial mass.

Massive stars burn through their fuel at a furious pace. They live fast and die young, exploding after just a few million years. Meanwhile, a star with the mass of our Sun has enough fuel to burn for ten billion years. The smallest red dwarfs sip their fuel so slowly that they can live for a trillion years. That is longer than the universe has currently existed.