We present an IDL graphical user-interface-driven software package designed for the analysis of exoplanet transit light curves. The Transit Analysis Package (TAP) software uses Markov Chain Monte Carlo (MCMC) techniques to fit light curves using the analytic model of Mandal and Agol (2002). The package incorporates a wavelet-based likelihood function developed by Carter and Winn (2009), which allows the MCMC to assess parameter uncertainties more robustly than classic 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. This paper describes the software release and provides applications to new and existing data. Reanalysis of ground-based observations of TrES-1b, WASP-4b, and WASP-10b (Winn et al., 2007, 2009; Johnson et al., 2009; resp.) and space-based Kepler 4b–8b (Kipping and Bakos 2010) show good agreement between TAP and those publications. We also present new multi-filter light curves of WASP-10b and we find excellent agreement with previously published values for a smaller radius. 1. Introduction The thriving field of exoplanet science began when Doppler techniques reached the precision required to detect the radial velocity (RV) variations of stars due to their orbital interactions with planets [1, 2]. The first detection of an exoplanet orbiting a main sequence star was followed closely by dozens more (51 Pegasi b; [3], see also, [4, 5]). To date, this technique has supplied the vast majority of knowledge—both detection and characterization—of exoplanets and their environments. Five years later the first photometric observation of an exoplanet transiting the stellar disk of its parent star provided a new, rich source of information on exoplanet systems (HD 209458; [6–8]). Transit measurements provide the true masses and radii of the planet and present many opportunities for diverse followup science [9, 10]. Unlike Doppler RV exoplanet signatures, transits affect observations only during the actual event so survey missions capable of constantly monitoring stars are needed to detect exoplanets by their transits. Today, such dedicated wide field transit survey missions have begun to keep pace with Doppler RV surveys and are ushering in a new era of exoplanetary science. The bulk of this
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