Trigo-Rodríguez, J. M.; García-Hernández, D. A.; Lugaro, M.; Karakas, A. I.; van Raai, M.; García Lario, P.; Manchado, A.
Bibliographical reference
Meteoritics & Planetary Science, vol. 44, Issue 5, p.627-641
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7
2009
Citations
34
Refereed citations
30
Description
We demonstrate that a massive asymptotic giant branch (AGB) star is a
good candidate as the main source of short-lived radionuclides in the
early solar system. Recent identification of massive (4-8 M?) AGB stars
in the galaxy, which are both lithium- and rubidium-rich, demonstrates
that these stars experience proton captures at the base of the
convective envelope (hot bottom burning), together with high-neutron
density nucleosynthesis with 22Ne as a neutron source in the He shell
and efficient dredge-up of the processed material. A model of a 6.5 M?
star of solar metallicity can simultaneously match the abundances of
26Al, 41Ca, 60Fe, and 107Pd inferred to have been present in the solar
nebula by using a dilution factor of 1 part of AGB material per 300
parts of original solar nebula material, and taking into account a time
interval between injection of the short-lived nuclides and consolidation
of the first meteorites equal to 0.53 Myr. Such a polluting source does
not overproduce 53Mn, as supernova models do, and only marginally
affects isotopic ratios of stable elements. It is usually argued that it
is unlikely that the short-lived radionuclides in the early solar system
came from an AGB star because these stars are rarely found in star
forming regions, however, we think that further interdisciplinary
studies are needed to address the fundamental problem of the birth of
our solar system.
Related projects
Nucleosynthesis and molecular processes in the late stages of Stellar Evolution
Low- to intermediate-mass (M < 8 solar masses, Ms) stars represent the majority of stars in the Cosmos. They finish their lives on the Asymptotic Giant Branch (AGB) - just before they form planetary nebulae (PNe) - where they experience complex nucleosynthetic and molecular processes. AGB stars are important contributors to the enrichment of the
Domingo Aníbal
García Hernández