Template:ASTR508/Assignment1

Part 1

Using the estimate of the central temperature of the Sun that I derived in class and the equation for radiative energy transport, estimate the luminosity of the Sun if the opacity is given by electron scattering 0.4 cm²g^-1 or by free-free opacity using the mean density and the central temperature of the Sun. Here is the formula for the absorption coefficient in c.g.s. units and its relationship to the free-free opacity $\kappa _{ff}$:

$\alpha _{ff}=\kappa _{ff}\rho =1.7\times 10^{-25}T^{-7/2}n_{e}n_{i}g_{R}$

Take $Z=g_{R}=1$. $n_{e}$ and $n_{i}$ are the number densities of electrons and ions respectively. $Z$ is the atomic number and $g_{R}$ is the Rosseland mean Gaunt factor.

Part 2

Complete the MESA exercises at the end of chapter one of Stellar Astrophysics .

The easiest way to get the code for the exercises is to download the repository on GitHub at [1].

Also please download [2] to help you get started with MESA>