PX282 - D2 - energy generation and transport

energy generation

considering the energy generation rate per unit mass in the shell, $ϵ [J s^{- 1} k g^{- 1}]$
the mass of the shell: $d M = 4 π r^{2} ρ d r$
the energy from the shell: $E = 4 π r^{2} ρ ϵ d r$
the luminosity, ie total energy:

\frac{d L_{r}}{d r} = 4 π r^{2} ρ ϵ

energy must flow from the core to the surface of a star as the core temperature will be higher that the surface temperature
the primary mechanisms in which this happens:
- radiation
- convection