The Breakout of Astrophysical Shocks

Shockwaves are abundant in astrophysics, from gamma ray bursts, to supernovae to planetary collisions.

In many cases such shocks emerge from the edge of the system, be it the surface of the planet or the edge of the star.

We discuss the physics of such shocks. Interesting hydrodynamics solutions allowing acceleration of shocks as they propagate towards the edge, as well as deviation from equilibrium as the dynamical and diffusion timescales become short and photons leak out of the systems. These processes determine the first signals we see from a supernovae or from the electromagnetic counterpart of gravitational wave sources such as neutron star mergers.

This dynamics will also set the amount of atmosphere ejected from planets in the process of their formation.