An analysis of CoRoT multicolour photometry of exoplanets

Abstract

We analysed the chromatic data of the planetary transits observed with CoRoT to supply homogeneous time series in each of the CoRoT colours. In a first step, we cleaned the chromatic light curves from the contamination of nearby stars and removed outliers and trends caused by anything different from the planetary transits. Then, we simultaneously fitted the chromatic transits of each planet, obtaining a common solution for the orbital parameters i, t0 and a/Rs, with a particular care in the fitting for different limb-darkening parameters. The planet-to-star radius ratios in the CoRoT colours are compatible when considering one planet at a time, but the ensemble of low-mass planets seems to show a peculiar behaviour of the radius ratios. © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.