Astrophysics & Particle Physics-APPC 2026

Stellar nucleosynthesis refers to how stars generate chemical elements by combining lighter nuclei into heavier ones in their cores or through explosive processes. This basic astrophysical process forms the majority of the universe's elements, ranging from helium and carbon to iron and beyond, determining the chemical nature of galaxies and planetary systems.Main-sequence stars burn hydrogen through the proton-proton chain in low-mass stars and the CNO cycle in high-mass stars, metabolizing hydrogen to helium. When stars age, helium burning creates carbon and oxygen by the triple-alpha process.

In larger stars, high-level fusion processes create elements like neon, magnesium, silicon, and iron from carbon, oxygen, and silicon burning.Observations of stellar spectra, supernova remnants, and the composition of meteorites serve to provide evidence of nucleosynthesis in operation. Nucleosynthesis is also responsible for explaining elemental abundance patterns in the galaxy and the production of matter available for planets and life.In short, stellar nucleosynthesis is the driving force of element formation in the universe. Through the merging of lighter elements into heavier ones, stars power stellar evolution, galactic chemical enrichment, and planetary and life formation. Nucleosynthesis gives us a glimpse into the life cycle of stars as well as the cosmic origin of the elements.