KOI 3278

This contains a stand-alone version of the code used to analyze the self-lensing binary system KOI-3278, as it appears in Science. It will reproduce the bulk of our analysis, including the MCMC modeling and the key figures, notably Figure 2 of the main text.

If you make use of this code please cite our work: Kruse & Agol, Science 344, 275 (2014).

We have also included the PARSEC isochrones used (PARSECv1.1/) as well as wget scripts to download the Kepler light curves (to lightcurve/) and white dwarf models from Pierre Bergeron (wdmodels/). See the README files within the subdirectories for more information.

Everything can be run using python assuming the following packages are installed (most are defaults in every python installation):

• sys
• os
• subprocess
• numpy
• scipy
• matplotlib
• glob
• astropy
• emcee

To reproduce all that we have done, one can simply run the shell script ./run.sh and all the figures should appear. This procedure should take less than a minute to complete. It may take slightly longer on the first run as the wget scripts download the necessary data files.

If you would like to generate the table of median model values and their one-sided error bars, you can change the texout variable in mcmc_analyze.py from None to any file name. This will take a couple minutes to complete.

Finally, if you would like to perform your own MCMC run, you can change the domcmc variable in mcmc_run.py from False to True. The length of the run will depend on the number of walkers and iterations (also chosen as variables in the file), but with the defaults it will take ~24 hours.