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(physics, astronomy) Any of several processes that lead to the synthesis of heavier atomic nuclei.

Diagram illustration the creation of new elements by the alpha process

(physics, astronomy) Any of several processes that lead to the synthesis of heavier atomic nuclei.

Periodic table showing the currently believed origins of each element. Elements from carbon up to sulfur may be made in stars of all masses by charged-particle fusion reactions. Iron group elements originate mostly from the nuclear-statistical equilibrium process in thermonuclear supernova explosions. Elements beyond iron are made in high-mass stars with slow neutron capture (s-process), and by rapid neutron capture in the r-process, with origins being debated among rare supernova variants and compact-star collisions. Note that this graphic is a first-order simplification of an active research field with many open questions.

(physics, astronomy) Any of several processes that lead to the synthesis of heavier atomic nuclei.

Abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, residuals within the paradigm of the Big Bang. The next three elements (Li, Be, B) are rare because they are poorly synthesized in the Big Bang and also in stars. The two general trends in the remaining stellar-produced elements are: (1) an alternation of abundance of elements according to whether they have even or odd atomic numbers, and (2) a general decrease in abundance, as elements become heavier. Within this trend is a peak at abundances of iron and nickel, which is especially visible on a logarithmic graph spanning fewer powers of ten, say between logA=2 (A=100) and logA=6 (A=1,000,000).