Abstract :
An overview of the role of giant resonances in three different astrophysical schemes is given. These studies are possible thanks to the recent advent of microscopic QRPA models based on a single energy functional including pairing effects. First the existence of collective modes in the inner crust of neutron stars is discussed. Second, the dipole strength being a major component of the nuclear statistical (de-)excitation mechanism, it is crucial to predict the E1 strength on several hundreds of neutron-rich nuclei involved in the r-process, which can occur from a decompression of the neutron star crust. Finally a description for the propagation of the Ultra High Energy Cosmic Rays (UHECR), from an extra-Galactic source towards the Earth, is necessary in order to solve the mystery of their composition. UHECR may be composed of protons and nuclei lighter than Iron.
