All live a long time, but some live longer than others. The densest ones last longest because they take longer to burn up. When the core burns up and disappears, hydrogen starts to burn up the star's shell. This makes the shell glow with a helium fire, and the star is called a red giant. When all the nuclear energy burns up, the star is called a white dwarf.
White dwarfs are very, very dense.
Then, the star's particles turn atomic, and the star explodes. The exploding star is called a supernova. It shines very brightly, and then it disappears. The life of a star is over. Return to Content-ESL Table of Contents .