EPJ Web Conf. EPJ Web Conf. Nuclear physics in the N≈126 region relevant for the $r$ process Podolyák Zsolt CERN Surrey U. 2023 279 Understanding how the heavy chemical elements are made in the astrophysical $r$-process requires information on both the properties of the nuclei involved and that of the environment. The availability of experimental information on the neutron-rich N∼126 nuclei is discussed, with emphasis on phenomena specifically relevant to this region: the large role of first-forbidden $\beta$ decays, and that of the $\Delta n = 0$ selection rule in Gamow-Teller decays. The development of nuclear data bases by combining different theoretical approaches is suggested. research-article