Shock wave emergence at the stellar surface and the subsequent gas expansion into a vacuum : the sphericity involvement

A solution is constructed to describe the shock wave passage through the outer envelope of the star and the following stellar matter expansion into a vacuum. The solution takes into account the sphericity of the flow in neighborhood of the stellar surface. Calculations are performed for the case γ=4/3, n=3 (γ is the adiabatic index, and n is the peripheric politropic index). At the stage of the shock wave emergence, the sphericity is shown to affect mostly the spatial distributions of density and pressure by increasing their slopes from the surface to the center of the star