Lithium production in the merging of white dwarf stars

The origin of R Coronae Borealis stars has been elusive for over 200 years. Currently, two theories for their formation have been presented. These are the final flash scenario, in which a dying asymptotic giant branch star throws off its atmosphere to reveal the hydrogen poor, heavily processed mate...

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Detalles Bibliográficos
Autores principales: Longland, R., Lorén Aguilar, P., José, J., García Berro, E., Althaus, Leandro Gabriel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2012
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83974
Aporte de:
id I19-R120-10915-83974
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
abundances
Nuclear reactions
nucleosynthesis
Stars: abundances
Stars: AGB and post-AGB
Stars: evolution
White dwarfs
spellingShingle Ciencias Astronómicas
abundances
Nuclear reactions
nucleosynthesis
Stars: abundances
Stars: AGB and post-AGB
Stars: evolution
White dwarfs
Longland, R.
Lorén Aguilar, P.
José, J.
García Berro, E.
Althaus, Leandro Gabriel
Lithium production in the merging of white dwarf stars
topic_facet Ciencias Astronómicas
abundances
Nuclear reactions
nucleosynthesis
Stars: abundances
Stars: AGB and post-AGB
Stars: evolution
White dwarfs
description The origin of R Coronae Borealis stars has been elusive for over 200 years. Currently, two theories for their formation have been presented. These are the final flash scenario, in which a dying asymptotic giant branch star throws off its atmosphere to reveal the hydrogen poor, heavily processed material underneath, and the double degenerate scenario, in which two white dwarfs merge to produce a new star with renewed vigour. Some theories predict that the temperatures reached during the latter scenario would destroy any lithium originally present in the white dwarfs. The observed lithium content of some R Coronae Borealis stars, therefore, is often interpreted as an indication that the final flash scenario best describes their formation. In this paper, we show that lithium production can, indeed, occur in the merging of a helium white dwarf with a carbon-oxygen white dwarf if their chemical composition, particularly that of <SUP>3</SUP>He, is fully considered. The production mechanism is described in detail, and the sensitivity of lithium production to the merger environment is investigated. Nucleosynthesis post-processing calculations of smoothed-particle hydrodynamics (SPH) tracer particles are performed to show that any lithium produced in these environments will be concentrated towards the cloud of material surrounding the R CrB star. Measurements of the lithium content of these clouds would, therefore, provide a valuable insight into the formation mechanism of R CrB stars.
format Articulo
Articulo
author Longland, R.
Lorén Aguilar, P.
José, J.
García Berro, E.
Althaus, Leandro Gabriel
author_facet Longland, R.
Lorén Aguilar, P.
José, J.
García Berro, E.
Althaus, Leandro Gabriel
author_sort Longland, R.
title Lithium production in the merging of white dwarf stars
title_short Lithium production in the merging of white dwarf stars
title_full Lithium production in the merging of white dwarf stars
title_fullStr Lithium production in the merging of white dwarf stars
title_full_unstemmed Lithium production in the merging of white dwarf stars
title_sort lithium production in the merging of white dwarf stars
publishDate 2012
url http://sedici.unlp.edu.ar/handle/10915/83974
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AT lorenaguilarp lithiumproductioninthemergingofwhitedwarfstars
AT josej lithiumproductioninthemergingofwhitedwarfstars
AT garciaberroe lithiumproductioninthemergingofwhitedwarfstars
AT althausleandrogabriel lithiumproductioninthemergingofwhitedwarfstars
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