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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 model for the formation of this category of supernova is a close binary star system. The larger of the two stars is the first to evolve off the main sequence, and it expands to form a red giant. The two stars now share a common envelope, causing their mutual orbit to shrink.
Artist's conception of a white dwarf, right, accreting hydrogen from the Roche lobe of its larger companion star A nova (pl. novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", Latin for "new") that slowly fades over weeks or months.
When two neutron stars collide, a significant amount of neutron-rich matter may be ejected which then quickly forms heavy elements. Cosmic ray spallation is a process wherein cosmic rays impact nuclei and fragment them. It is a significant source of the lighter nuclei, particularly 3 He, 9 Be and 10,11 B, that are not created by stellar ...
Type II is subdivided into two classes, depending on the shape of the light curve. The light curve for a Type II-L supernova shows a steady ( linear ) decline following the peak brightness. By contrast, the light curve of a Type II-P supernova has a distinctive flat stretch (called a plateau ) during the decline; representing a period where the ...
In the case of a nova, the infalling matter causes a hydrogen fusion surface explosion that does not disrupt the star. [ 13 ] Type Ia supernovae differ from Type II supernovae , which are caused by the cataclysmic explosion of the outer layers of a massive star as its core collapses, powered by release of gravitational potential energy via ...
However, most of the nucleosynthesis in the mass range A = 28–56 (from silicon to nickel) is actually caused by the upper layers of the star collapsing onto the core, creating a compressional shock wave rebounding outward. The shock front briefly raises temperatures by roughly 50%, thereby causing furious burning for about a second.
[21] [22] He published his observations in the small book De nova et nullius aevi memoria prius visa stella (Latin for "Concerning the new and previously unseen star") in 1573. It is from the title of this book that the modern word nova for cataclysmic variable stars is derived. [23] Multiwavelength X-ray image of the remnant of Kepler's ...