<tt>batman</tt>: BAsic Transit Model cAlculatioN in Python

Abstract

I introduce batman, a Python package for modeling exoplanet transit light\ncurves. The batman package supports calculation of light curves for any\nradially symmetric stellar limb darkening law, using a new integration\nalgorithm for models that cannot be quickly calculated analytically. The code\nuses C extension modules to speed up model calculation and is parallelized with\nOpenMP. For a typical light curve with 100 data points in transit, batman can\ncalculate one million quadratic limb-darkened models in 30 seconds with a\nsingle 1.7 GHz Intel Core i5 processor. The same calculation takes seven\nminutes using the four-parameter nonlinear limb darkening model (computed to 1\nppm accuracy). Maximum truncation error for integrated models is an input\nparameter that can be set as low as 0.001 ppm, ensuring that the community is\nprepared for the precise transit light curves we anticipate measuring with\nupcoming facilities. The batman package is open source and publicly available\nat https://github.com/lkreidberg/batman .\n