Transit Analysis Package (TAP & autoKep)



IDL GUI for state of the art Markov Chain Monte Carlo (MCMC) fitting of extrasolar planet transit light curves


IDL GUI for Preparing NASA Kepler light curves for analysis by TAP.

Download TAP and autoKep:                                           

The resulting transit light curve provides salient details regarding the geometry of an exoplanet system and physical scales of the planet and star with no need to spatially resolve the event.

The autoKep GUI is designed to provide streamlined transit light curves from MAST Kepler archive fits files.  Isolating, normalizing, and fitting out of transit variations to each light curve in a Kepler dataset is a non-trivial task.  Doing so by hand provides ample opportunities for error and/or nonstandard reduction per light curve.  autoKep avoids these issues and greatly increases efficiency by providing a simple graphical interface to extract the transit data from Kepler MAST light curves.

Exoplanet Transit:

A planet passing between its host star and an observer blocks a region of the stellar disk, imprinting a unique signature on the observed stellar flux.

We present an IDL package designed for the analysis of extrasolar planet (ESP) transit light curves.

The Transit Analysis Package (TAP) software utilizes Markov Chain Monte Carlo (MCMC) techniques to fit transit light curves using the Mandel & Agol (2002) model.  TAP uses EXOFAST (Eastman, Agol, & Gaudi, in prep.) to calculate the M&A models. The package incorporates a wavelet based likelihood function developed by Carter & Winn (2009) which allows the MCMC to assess parameter uncertainties more robustly than classic χ2 methods by parameterizing uncorrelated “white” and correlated “red” noise.

The software is able to simultaneously analyze multiple transits observed in different conditions (instrument, filter, weather, etc). The graphical interface allows for the simple execution and interpretation of Bayesian MCMC analysis tailored to a user’s specific data set and has been thoroughly tested on ground-based and Kepler photometry.

January 30 2011

Watch TAP in action! (.mp4)