Stars and Nuclei: A Tribute to Manuel Forestini
T. Montmerle and C. Kahane (eds)
EAS Publications Series, 19 (2006) 199-219DOI: 10.1051/eas:2006033
Presolar Grains and AGB Stars
M. Lugaro1 and R. Gallino2 1
Astronomical Institute, University of Utrecht, Postbus
80000, 3508 TA, Utrecht, The Netherlands
2
Dipartimento di Fisica Generale, Università di
Torino and Sezione INFN di Torino, via Giuria 1, 10125
Torino, Italy, and Centre for Stellar and Planetary Astrophysics, School of
Mathematical Sciences, Monash University 3800, Victoria, Australia
Abstract
The recent discovery of microscopic grains of presolar origin in primitive
meteorites has opened a new field of astrophysics where scientists from different
disciplines, from nuclear physics to astronomy, chemistry and mineralogy, are
required to work together. In this inter-disciplinary field information on the
composition of stars is obtained through laboratory analysis of meteoritic rocks.
We review the main features of the composition of presolar SiC and oxide grains
that are believed to have originated in Asymptotic Giant Branch (AGB) stars.
High-precision laboratory measurements of the isotopic composition of these types
of presolar grains represent the most detailed record of the composition of AGB
stars, and thus a major constraint for the theoretical models of these stars. In
particular, the CNO and Al/Mg compositions can set constraints on extra-mixing
processes in red giant and AGB stars. The composition of heavy elements produced
by
slow neutron captures (
s-process) yields a variety of information on the
grain parent stars, including their masses and the way neutron sources operate.
© EAS, EDP Sciences 2006
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