Heavy-elements in metal-poor stars: an UV perspective

The site(s) of the r-process(es) is(are) not completely defined, and several models have been proposed. Observed abundances are the best clues to bring some light to this field, especially the study of the extremely metal-poor (EMP) Galactic halo stars. Many elements can be measured using ground-based facilities already available, but the ultraviolet window also presents a rich opportunity in terms of chemical abundances of heavy elements. In fact, for some elements only the UV transitions are strong enough to be useful. Focusing on the project of the Cassegrain U-Band Brazilian Spectrograph (CUBES), we discuss the science case for heavy elements in metal-poor stars, describing the useful lines of trans-Fe elements present in the UV region. Lines in the far UV are also discussed.