Abstract: Weak interactions play an important role in a variety of astrophysical scenarios, and reliable weak interaction rates are important for accurate simulations. The study of spin-isospin excitations of nuclei through charge-exchange reactions is a useful tool for benchmarking, constraining, and guiding the development of nuclear models that are used for estimating astrophysical weak reaction rates. The charge-exchange group has established a weak-rate library that can be used in a variety of astrophysical simulations and is continuously updated and improved on the basis of new experimental and theoretical results.

In particular, the group has focused on studies of the collapse phase of core-collapse supernovae, in which electron-captures on medium heavy nuclei play a particularly important role. Sensitivity studies have pinpointed key areas of interest in the chart of nuclei (in particular around N=50, just above ⁷⁸Ni), which have been the primary focus on recent experimental, theoretical, and astrophysical studies. The presentation will focus on these recent efforts, and give an outlook for the development of new experimental tools, such as the (d,²He) and (p,n+γ) reactions in inverse kinematics.