On Barium Stars and the s-Process in AGB Stars

A new large set of homogeneous high resolution spectra of Barium (Ba) stars makes it now possible to compare the observational data from only one study with different AGB models. The Ba star data show an incontestable increase of the hs-type/ls-type element ratio (for example, [Ce/Y]) with decreasing metallicity. This trend in the Ba star observations is predicted by low mass, non-rotating AGB models where \(^{13}\)C is the main neutron source.