22Ne makes 12C laminar flames burn faster in white dwarf supernovae
| Type Ia SNe |
22Ne makes 12C laminar flames burn faster in white dwarf supernovae |
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Type Ia supernovae result from the thermonuclear incineration of a white dwarf star. They are currently the premier standard candle for measuring the geometry of the universe and for probing the properties of the "dark energy" that is making the universe accelerate at an accelerating rate. Despite their importance, many of the details of the explosion remain poorly understood. One unanswered question is how the composition of the white dwarf affects the explosion. Michigan State University graduate student David Chamulak has demonstrated that the enrichment of the white dwarf with neon-22 (formed during the fusion of helium in the progenitor star) speeds up the flame in the early stages of the explosion. This finding means that distant supernovae, which exploded long ago when the universe was poorer in heavy elements, are somewhat different than nearby supernovae. It remains to be seen whether this translates into any systematic errors in using type Ia supernovae as "standard candles." |
| Credit: David A. Chamulak, Edward F. Brown (Michigan State University and the National Superconducting Cyclotron Laboratory) , and Francis X. Timmes (LANL). This material is based upon work supported by the National Science Foundation (NSF) under Grant No. AST-0507456, by the Joint Institute for Nuclear Astrophysics at MSU under NSF-PFC grant PHY 02-16783, and by the US Department of Energy via its contract W-7405-ENG-36 to Los Alamos National Laboratory. Any opinions, findings, and conclusions or recomendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. Image credit: High-Z Supernova Search Team, HST, NASA | |