r-process observations

The r-process nucleosynthesis in the Universe is constrained by observations of chemical abundances of the Solar System and those of old stars that should record the products of the r-process events in the early Universe. This review provides a brief overview of the observational technique to determine chemical abundances of stars. Targets of observations are stars in different populations of the Milky Way Galaxy and surrounding dwarf galaxies, providing different kind of constraints on the understanding of the r-process. Recent progress in observational studies to identify the r-process sites are also reviewed.