Roland Diehl, Max-Planck-Institut (MPE) and Technische Universität München (TUM), Garching, Germany — January 19, 2026

Nuclear astrophysics includes the study of signatures from atomic nuclei, as they convey information about high-energy processes in objects throughout the universe.
The astrophysical processes are most prominently the creation of new nuclei and the cumulative enrichment of cosmic gas with elements heavier than helium, and these are reflected most directly in nuclear lines of specific isotopes.
Suitable astronomical tools to observe such physical processes are telescopes operating in the MeV energy band. We will review characteristics of nuclear-emission telescopes, and discuss selected recent achievements in gamma-ray spectroscopy, that result from measurements of gamma rays from characteristic radioactive isotopes freshly produced in different sources, and from annihilations of positrons that are by-products of beta decays.
Herein we will address stars and their internal structure, as well as supernova explosions and the transport of nucleosynthesis ejecta in interstellar medium.