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Supernova nucleosynthesis is the nucleosynthesis of chemical elements in supernova explosions.. In sufficiently massive stars, the nucleosynthesis by fusion of lighter elements into heavier ones occurs during sequential hydrostatic burning processes called helium burning, carbon burning, oxygen burning, and silicon burning, in which the byproducts of one nuclear fuel become, after ...
The first direct proof that nucleosynthesis occurs in stars was the astronomical observation that interstellar gas has become enriched with heavy elements as time passed. As a result, stars that were born from it late in the galaxy, formed with much higher initial heavy element abundances than those that had formed earlier.
Fusing with additional helium nuclei can create heavier elements in a chain of stellar nucleosynthesis known as the alpha process, but these reactions are only significant at higher temperatures and pressures than in cores undergoing the triple-alpha process.
Scientists discovered a method to create element 116 using a titanium beam, paving the way for future synthesis of element 120, the "holy grail" of chemistry.
The dashed line shows the combined energy generation of the p-p and CNO processes within a star. The stable alpha elements are: C, O, Ne, Mg, Si, and S. The elements Ar and Ca are "observationally stable". They are synthesized by alpha capture prior to the silicon fusing stage, that leads to Type II supernovae. Si and Ca are purely alpha ...
Clayton calculated the first time-dependent models of the s-process in 1961 [15] and of the r-process in 1965, [16] as well as of the burning of silicon into the abundant alpha-particle nuclei and iron-group elements in 1968, [17] [18] and discovered radiogenic chronologies [19] for determining the age of the elements.
Abundance peaks for the r-process occur near mass numbers A = 82 (elements Se, Br, and Kr), A = 130 (elements Te, I, and Xe) and A = 196 (elements Os, Ir, and Pt). The r -process entails a succession of rapid neutron captures (hence the name) by one or more heavy seed nuclei , typically beginning with nuclei in the abundance peak centered on 56 ...
The elements heavier than iron with origins in dying low-mass stars are typically those produced by the s-process, which is characterized by slow neutron diffusion and capture over long periods in such stars. A calculable model for creating the heavy isotopes from iron seed nuclei in a time-dependent manner was not provided until 1961. [7]