Everything you wanted to know about New Physics and Supernovae: but were afraid to ask.

Core-collapse supernovae (CCSN) are efficient laboratories to explore physics beyond the standard model (SM). In particular, they have been used to put strong constraints on axion and axion like particles, and on many other motivated extensions of the SM. In this talk I will first introduce the subject and then focus on some new results. In particular, I will describe a particular class of CCSNe, the Low Energy CCSNe, and show how they can be used as efficient beam dump experiments to severely constrain radiative particle decays. Finally, I will conclude talking about exciting prospects for the next years.