nucleosynthetic

Nucleosynthetic is an adjective describing processes or products related to nucleosynthesis, the set of physical mechanisms by which atomic nuclei are created from preexisting protons and neutrons. In astronomy and cosmochemistry, nucleosynthetic pathways operate in a variety of environments and epochs, shaping the elemental and isotopic composition of the universe. The study of nucleosynthetic outcomes includes analyzing yields, isotopic ratios, and spectral signatures found in stars, planetary systems, and primitive meteorites.

In stars, hydrogen burning through the proton-proton chain and the CNO cycle converts hydrogen into helium, providing the energy to power stellar luminosities. In more massive stars, successive fusion stages build elements up to iron in the core, a sequence often referred to as stellar nucleosynthesis. Beyond fusion, neutron capture processes play a major role: the slow s-process occurs in asymptotic giant branch stars and gradually builds heavier isotopes, while the rapid r-process, likely triggered in explosive environments such as core-collapse supernovae or neutron-star mergers, rapidly synthesizes many neutron-rich nuclei. The p-process creates proton-rich isotopes via photodisintegration or proton captures.

Explosive nucleosynthesis during supernovae and neutron-star mergers contributes a substantial portion of the heavy elements observed in the universe. Nucleosynthetic theory and modeling, together with observational data, underpin our understanding of galactic chemical evolution and the origin of elements in the solar system.