On the timescales of SNIa and Kilonovae (KNe) explosions

The timescales of release of the products of stellar explosions are a fundamental ingredient to the modelling of chemical evolution of galaxies, and to interpret the abundance patterns in stars. While massive stars release their nuclear products on short timescales, the delay times from birth to death of SNIa and KNe span a wide range, so that their pollution of the ISM occurs over a long time. This induces specific patterns on the trend of some abundance ratios with increasing processing of the ISM providing us with a chemical clock. Different options exist for the distribution of the delay times of SNIa and of KNe, depending on the progenitor’s models and specific evolutionary paths. In this talk I will describe these various options and illustrate methods to constrain the distribution of the delay times of SNIa and of KNe from their observed rates in galaxies.