A star will die when all the hydrogen gas in its core is used up in nuclear reactions. The lifespan of a star is determined by the original mass of the star. A star with a big mass has a shorter life span compared to a star with a small mass. For example, stars that are 50 times bigger than the Sun live for only a few million years. Stars that are smaller than the Sun can live more than 10 billion years. A died star with become either a white dwarf , a black dwarf , a neutron star or black hole , depending on its size as shown in the figure below.