Template:ASTR508/Basic Stars, Basic MESA

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Basic Stars, Basic MESA

Reading Assignment

Chapter 1 of Stellar-Astrophysics Notes

Observations of Stars

ASTR508Ple.png

ASTR50847TucCMD.png

ASTR50847TucCMDcore.png

How to get MESA?

  1. Download the MESASDK from http://www.astro.wisc.edu/~townsend/static.php?ref=mesasdk and unpack
  2. Download the recent MESA source by following the instructions at http://mesa.sourceforge.net
  3. Create your setup.sh script to setup the environment variables for MESA and the MESASDK
  4. Run the setup.sh script
  5. Go to the MESA directory and run "./install"
  6. Get more help at http://mesastar.org/
  7. If you want to install ctioga2 with your MESASDK, follow my instructions at Ctioga2.

You can also use MESA-Web until you get your own copy working or Cocalc. If you have trouble installing your copy, please try

  1. MESA-Docker, or
  2. VMESA
  3. Class CoCalc/MESA Server

What does MESA do?

MESA Inlists:

  • sample_zams
  • create_zams

Assignment

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 :

Take . and are the number densities of electrons and ions respectively. is the atomic number and 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>