Speaker
Description
Recently, there have been hints that an increasing number of extrinsic stars (barium, CH and CEMP) could be enriched in chemical elements produced by the i-process (characterised by neutron densities $N_n \sim 10^{14-15}$ cm$^{-3}$) rather than by the s-process ($N_n \sim 10^{8}$ cm$^{-3}$) .
Different isotopic mixtures are predicted for the s-process on the one hand, and for the r- or i-processes on the other. After a brief review of previous isotopic composition determinations, we report on our investigation, based on high-resolution, high signal-to-noise HERMES and UVES spectra and non-LTE line synthesis, of the barium isotopic composition of extrinsic stars enriched in heavy elements.
We also report on a sample of extrinsic stars uncovered in Gaia DR3. We discuss their properties in terms of chemical abundances and binarity, as well as the overlap with existing catalogues of extrinsic stars.
