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In astrophysics, stellar nucleosynthesis is the creation of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. As a predictive theory, it yields accurate estimates of the observed abundances of the elements.
The x-process in cosmic rays is the primary means of nucleosynthesis for the five stable isotopes of lithium, beryllium, and boron. [3] As the proton–proton chain reaction cannot proceed beyond 4 He due to the unbound nature of 5 He and 5 Li, [ 4 ] and the triple-alpha process skips over all species between 4 He and 12 C, these elements are ...
Natural transmutation by stellar nucleosynthesis in the past created most of the heavier chemical elements in the known existing universe, and continues to take place to this day, creating the vast majority of the most common elements in the universe, including helium, oxygen and carbon.
While the total number of "catalytic" nuclei are conserved in the cycle, in stellar evolution the relative proportions of the nuclei are altered. When the cycle is run to equilibrium, the ratio of the carbon-12/carbon-13 nuclei is driven to 3.5, and nitrogen-14 becomes the most numerous nucleus, regardless of initial composition.
The prediction and then discovery of this energy resonance and process gave very significant support to Hoyle's hypothesis of stellar nucleosynthesis, which posited that all chemical elements had originally been formed from hydrogen, the true primordial substance.
Gamow discovered a theoretical explanation of alpha decay by quantum tunneling, invented the liquid drop model - the first mathematical model of the atomic nucleus, worked on radioactive decay, star formation, stellar nucleosynthesis, Big Bang nucleosynthesis (which he collectively called nucleocosmogenesis), predicted the existence of the ...
The ultimate source of cosmic dust are stars in which the elements – out of which stardust is composed of – are produced by fusion of hydrogen and helium or by explosive nucleosynthesis in supernovae. This stardust from various stellar sources is mixed in the interstellar medium and thermally processed in star forming regions. Solar System ...
The final stage in the stellar nucleosynthesis process is the silicon-burning process that results in the production of the stable isotope iron-56. [209] Any further fusion would be an endothermic process that consumes energy, and so further energy can only be produced through gravitational collapse.