Later This site tells the story of the history of the universe. Click Earlier and Later to follow the story.
Some red giants die quietly.
The contraction of the inner parts of the star releases heat which causes the outer parts to expand and gently get blown away. In this way the gas of old stars is released and can be formed into new stars. The inner part of the star continues to contract until it reaches the size of the Earth. Then its atoms are crushed together so tightly that their electrons begin to overlap. Because two electrons cannot occupy the same space, they repel each other.