Basic Formulae for the Exoplanetary Transit Model Calculation


O. Demircan1

1Çanakkale University Observatory, Çanakkale, Turkey;


Kopal’s unique formula of the eclipse functions were adopted for the computation of light curves of exoplanetary transits. The equations are functions of the fractional radii and fractional luminosity of the exoplanet and the parent star, the inclination of the orbit, and the limb-darkening coefficients of the parent star. Light curves can be solved for these parameters depending on the precision of the available observations. The equations are valid for any degree of limb darkening, as well as for any type of eclipses (transit, occultation, total, annularor partial). In the present formulation, orbit of the exoplanet around a star is assumed to be circular, and the projections of boththe star and the planet on the plane of the sky are also assumed to be circular discs. The formulation of the problem can be extended to cover the eccentric orbits, third light, and non-zero relative luminosity of the planet.

Keywords: Exoplanets, planetary transits, photometric observations, eclipsing binaries

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