Csillagászat (benne az asztrofizika és az űrtudomány)
The Barium (Ba) star phenomenon is unmissable from the study and understanding of
nucleosynthetic processes occuring in AGB stars. Ba stars belong to binary systems,
where the former AGB polluted the companion, a less evolved star, which became enriched
with material produced through the slow neuton capture process (s process). While
the AGB has evolved to a white dwarf, the currently observed Ba star preserves the
abundance pattern of the AGB, allowing us to test the imprints of the $s$ process.
Comparing different AGB nucleosynthetic models and Ba star abundances, we are able
to constrain the effect of the rotation velocity or the neutron source in the interior
of the AGB star. The trend in the Ba star observations is predicted by non-rotating
AGB models where 13C is the main neutron source. The results of the comparison of
models with initial AGB masses from an independent source and the analysis of 28 Ba
giant star abundances confirm that the polluting AGBs are of low mass.
