Standard Numerical Solution

The data file zams.dat and the Grace project file zams.agr have standard zero age main sequence models for a range of masses. The files are located on the computer system in /home/data/zams. An easy way to use the the Grace file is to copy it to a directory of your own with the command cp /home/data/zams/zams.agr ./ which will place it in your current working directory. After that, use Grace with the command xmgr zams.agr to interactively work with the data.

The data sets are labeled on the graph and also on the set labels. Look at the relative data for $L$, $T$, and $R$. Use Data $\rightarrow$ Transformations $\rightarrow$ Regression to open a window that allows you to fit the data to different functions. In this case you will use a power fit so select $y=A x^B$ from the menu and load the fitted values (the default).

1. Fit each of R, L, and T to a power law of the form used for 1-3 above.
2. Compare these fits to the numerical solutions with your simple model and comment on the differences. Do you think that different assumptions for your simple model would improve the comparison? For the relationship between mass and luminosity, what power law would you use for approximate calculations?