Fusion in Stars - Zoom Astronomy Search the Web. Search the Web with our sponsor, Overture. Nuclear Fusion and Nucleosynthesis Stars are giant nuclear reactors. In the center of stars, atoms are taken apart by tremendous atomic collisions that alter the atomic structure and release an enormous amount of energy. This makes stars hot and bright.
Nuclear fusion is an atomic reaction that fuels stars.
Stars are powered by nuclear fusion in their cores, mostly converting hydrogen into helium . The production of new elements via nuclear reactions is called nucleosynthesis. Each of us is made from atoms that were produced in stars and went through a supernova. Late in their lives, when the hydrogen becomes depleted, stars like our Sun can convert helium into oxygen and carbon. When their hydrogen becomes depleted, high mass stars convert helium atoms into carbon and oxygen, followed by the fusion of carbon and oxygen into neon, sodium, magnesium, sulfur and silicon.