We conclude with future prospects for studying light curve anomalies in exoplanetary transits. Here we describe how the EPTM works: (1) a theoretical light curve is calculated for an initial set of planetary parameters, RP, a, and i (2) an observed light curve is used to calculate χ2 for that theoretical curve (3) the planetary parameters are varied in a grid about their initial values to produce a multidimensional array of χ2 values and (4) the minimum valley in this χ2 array is used to select most probable values and confidence intervals of the planetary parameters. The EPTM also determined the length of the transit and the approximate start and end time of the ingress and egress. Based on the EPTM, XO-2 hosts a planet, XO-2b, with a planetary radius of R = 1.043 RJ, in a near circular orbit with semimajor axis a = 0.0360 AU and inclination angle i = 89.67. To establish and test the accuracy of the model, an observation of XO-2 was conducted on 2008 Mar 17 where time-series photometry of the transit of XO-2b was collected. (2006), where we include the confirmed non-zero eccentricity and derive a 24 micron planetary radius of R_P = 1.275 +- 0.082 R_J (where R_J = 1 Jovian radius), which is 1% larger than is we assume a circular orbit.Ī computer model, called the Exoplanetary Pixelization Transit Model (EPTM), is developed to calculate exoplanetary transit light curves and determine exoplanet properties from an observed transit light curve. We present a new few-parameter phenomenological model of light curves of eclipsing binaries and stars with transiting planets that is able to fit the. Furthermore, we use our model in a reanalysis of HD 209458 b archived data by Richardson et al. It is shown that a system with changing eccentricity and inclination may produce a long period transit time variation (LTTV). We aim to investigate three major effects our model predicts: i) the degeneracy in transit lightcurve solutions for eccentricity, e>0 ii) the asymmetry of the lightcurve and the resulting shift in the mid-transit time, Tmid iii) the effect of eccentricity on the ingress and egress slopes. Here, a new analytic model is proposed which operates for the more general case of an eccentric orbit. Equations have been previously presented by Seager & Mallen-Ornelas (2003) for the analysis of the total and trough transit lightcurve times to derive the ratio of semi-major axis to stellar radius, a/R*, in the case of circular orbits. Transiting planet lightcurves have historically been used predominantly for measuring the depth and hence ratio of the planet-star radii, p.
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