Cosmic nucleosynthesis

Synthesis of these elements occurred either by nuclear fusion including both rapid and slow multiple neutron capture or to a lesser degree by nuclear fission followed by beta decay.

It would also be necessary for the deuterium to be swept away before it reoccurs. Like to learn more. For a long time, this meant that to test BBN theory against observations one had to ask: The graph above shows the predicted abundance vs. The observed lithium abundance in stars is less than the predicted lithium abundance, by a factor of about 2.

The goal of the theory of nucleosynthesis is to explain the vastly differing abundances of the chemical elements and their several isotopes from the perspective of natural processes. Both light helium He3 and normal helium He4 are made, along with the radioactive form of hydrogen H3.

When two helium-3 nuclei collide, they form a nucleus of ordinary helium, helium-4 two protons and two neutronsand release two protons. Unsourced material may be challenged and removed. The subsequent nucleosynthesis of the heavier elements requires the extreme temperatures and pressures found within stars and supernovas.

Chapter 17: Cosmology

The half-life of the neutron is seconds. Larger quantities of these lighter elements in the present universe are therefore thought to have been restored through billions of years of cosmic ray mostly high-energy proton mediated breakup of heavier elements in interstellar gas and dust.

Creation of the Heavier Elements After the bulk of a star's hydrogen has been converted to helium by either the proton-proton or carbon-nitrogen-oxygen process, the stellar core contracts while the outer layers expand until sufficiently high temperatures are reached to initiate "helium-burning" by the triple-alpha process; in this process, three helium nuclei alpha particles are fused to make a carbon nucleus.

Eventually the temperature gets so low that the electrostatic repulsion of the deuterons causes the reaction to stop. The discrepancy is a factor of 2. See Handbook of Isotopes in the Cosmos for more data and discussion of abundances of the isotopes.

The proton-proton cycle operates in less massive and luminous stars like the sun, while the carbon-nitrogen-oxygen cycle which speeds up dramatically at higher temperatures dominates in more massive and luminous stars.


Eventually the temperature gets so low that the electrostatic repulsion of the deuterons causes the reaction to stop.

The atoms in your body — apart from the hydrogen — were all made in stars … by stellar nucleosynthesis. Deuterium peaks around seconds after the Big Bang, and is then rapidly swept up into helium nuclei.

The seminal review paper by E. There are no known post-Big Bang processes which can produce significant amounts of deuterium. Big Bang Cosmic ray spallation.

Hydrostatic nucleosynthesis Explosive nucleosynthesis Neutron capture nucleosynthesis.

Chapter 17: Cosmology

nucleosynthesis - (astronomy) the cosmic synthesis of atoms more complex than the hydrogen atom. astronomy, uranology - the branch of physics that studies celestial bodies and the universe as a whole.

synthesis - the process of producing a chemical compound (usually by. There are other ways new nuclei can be created, in the universe (other than BBN and stellar nucleosynthesis); for example, when a high energy particle (a cosmic.

Apr 30,  · Stellar nucleosynthesis also involves nucleosynthesis in supernovae. Primordial nucleosynthesis is the production of certain elements from the big bang model. The primordial elements include hydrogen, helium, and a small amount of lithium. nucleosynthesis or nucleogenesis, in astronomy, production of all the chemical elements [1] from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at the beginning of the universe (see nucleus [2]; nuclear energy [3]).


Dec 06,  · In physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than H-1, the normal, light hydrogen, during the early phases of the.

Cosmic nucleosynthesis
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Big Bang Nucleosynthesis