The outer layers of the star are blown off in an explosion triggered by the outward moving supernova shock, known as a Type II supernova that lasts days to months.Tags: Research Proposal Outline TemplateSecret Santa AssignerMarriage Is Private Affair EssayEssay On BureaucracyFilm DissertationsFamous Love EssaysBest Online Term PaperEssay Writing On Role Of Media In Bringing Public AwarenessAide En Dissertation
The pressure that supports the star's outer layers drops sharply.
As the outer envelope is no longer sufficiently supported by the radiation pressure, the star's gravity pulls its outer layers rapidly inward.
The latter synthesizes the lightest, most neutron-poor, isotopes of the heavy elements.
A supernova is a massive explosion of a star that occurs under two principal scenarios.
At these temperatures, silicon and other elements photodisintegrate by energetic thermal photons ejecting alpha particles.
Silicon burning differs from earlier fusion stages of nucleosynthesis in that it entails a balance between alpha-particle captures and their inverse photo ejection which establishes abundances all alpha-particle elements in the following sequence in which each alpha particle capture shown is opposed by its inverse reaction, namely, photo ejection of an alpha particle by abundant thermal photons: Zn photon In these circumstances of rapid opposing reactions the abundances are not determined by alpha-particle-capture cross sections; rather they are determined by the values that the abundances must assume in order to balance the speeds of the rapid opposing-reaction currents.
As a result of their ejection from supernovae, their abundances increase within the interstellar medium.
Elements heavier than nickel are created primarily by a rapid capture of neutrons in a process called the r-process.
In the pre supernova massive star this includes carbon burning, oxygen burning and silicon burning.
Much of that yield may never leave the star but disappear into its collapsed core.