World Library  
Flag as Inappropriate
Email this Article

Carbon detonation

Article Id: WHEBN0007195427
Reproduction Date:

Title: Carbon detonation  
Author: World Heritage Encyclopedia
Language: English
Subject: White dwarf, Supernova, Cataclysmic variable star, Helium flash, Chandrasekhar limit
Publisher: World Heritage Encyclopedia

Carbon detonation

Carbon detonation is the violent reignition of thermonuclear fusion in a white dwarf, which produces a Type Ia supernova. A white dwarf undergoes carbon detonation only if it has a normal binary star companion close enough for the dwarf star to siphon sufficient amounts of matter onto itself, the siphoned matter having been expelled during the process of the companion's own late stage stellar evolution.

If the companion supplies enough matter to the dead star, the white dwarf's internal pressure and temperature will rise high enough to fuse the previously unfusable carbon in the white dwarf's core. Carbon detonation generally occurs when the accreted matter pushes the white dwarf's mass close to the Chandrasekhar limit of roughly 1.4 solar masses.

While heat is released by the fusion reactions, pressure initially is due almost entirely to electron degeneracy rather than thermal energy and thus does not increase much, inhibiting expansion of the star (until too late) and allowing temperature and thus the rate of fusion to increase dramatically in a runaway process. The resumption of fusion spreads outward in a series of uneven, expanding "bubbles" exhibiting Rayleigh–Taylor instability.[1] Within the fusion area, the increase in heat with unchanged volume results in an exponentially rapid increase in the rate of fusion – a sort of supercritical event as thermal pressure increases boundlessly. With no hydrostatic equilibrium possible, this triggers a "thermonuclear flame," and an explosive eruption through the dwarf star's surface that completely disrupts it, seen as a Ia supernova.

This process, of a volume supported by electron degeneracy pressure instead of thermal pressure gradually reaching conditions capable of igniting runaway fusion, is also found in a less dramatic form in a helium flash in the core of a sufficiently massive red giant star.

See also


  1. ^

External links

  • JINA: Type Ia Supernova Flame Models
  • A Computer Simulation of Carbon Detonation/Deflagration
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.