  The relativistic quasiparticle time-blocking approximation (RQTBA) is applied
to the description of nuclear excitation modes of astrophysical interest. This
method is based on the meson-nucleon Lagrangian and goes beyond the standard
relativistic quasiparticle random-phase approximation (RQRPA) by treating the
coupling between single quasiparticles and collective vibrations of the
nucleus. We calculate electric dipole transitions and Gamow-Teller modes in the
(p,n) direction in a few Sn isotopes and obtain the rates of (n,$\gamma$)
reaction and $\beta^-$-decay processes, which govern the r-process
nucleosynthesis, in a unified RQTBA framework. Gamow-Teller transitions in the
(n,p) branch, which in principle can serve for the modeling of stellar
evolution, are also investigated, and $^{90}$Zr is taken as a study case.
