Observational nuclear astrophysics: neutron-capture element abundances
  in old, metal-poor stars
  The chemical abundances of metal-poor stars provide a great deal of
information regarding the individual nucleosynthetic processes that created the
observed elements and the overall process of chemical enrichment of the galaxy
since the formation of the first stars. Here we review the abundance patterns
of the neutron-capture elements (Z > 38) in those metal-poor stars and our
current understanding of the conditions and sites of their production at early
times. We also review the relative contributions of these different processes
to the build-up of these elements within the galaxy over time, and outline
outstanding questions and uncertainties that complicate the interpretation of
the abundance patterns observed in metal-poor stars. It is anticipated that
future observations of large samples of metal-poor stars will help discriminate
between different proposed neutron-capture element production sites and better
trace the chemical evolution of the galaxy.
