stellarfusion

Stellar fusion is the process by which two atomic nuclei combine to form a heavier nucleus, releasing a significant amount of energy in the process. This phenomenon is the primary power source for stars, including the Sun, and is fundamental to the formation of heavier elements in the universe.

In the core of a star, extreme temperatures and pressures allow nuclei to overcome their natural electrostatic repulsion, enabling fusion reactions. The most common fusion reaction in stars involves hydrogen nuclei (protons), which fuse to form helium through a series of steps known as the proton-proton chain or the carbon-nitrogen-oxygen (CNO) cycle, depending on the star’s mass and temperature. Each fusion reaction converts a small amount of mass into energy, following Einstein’s mass-energy equivalence principle (E=mc²).

Stellar fusion is responsible for the production of elements up to iron in the periodic table. Reactions fusing lighter elements into heavier ones release energy, but beyond iron, fusion requires energy input rather than producing it. This is why stars primarily fuse elements up to iron before undergoing later stages of stellar evolution, such as supernova explosions, which disperse heavier elements into space.

Fusion is also being studied as a potential energy source on Earth, known as nuclear fusion. While stellar fusion occurs naturally under extreme conditions, controlled fusion research aims to replicate these processes in laboratory settings to produce clean, abundant energy. Challenges include achieving and maintaining the necessary temperatures and confinement of plasma to sustain fusion reactions.