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arXiv · 0909.3256

A planetary eclipse map of CoRoT-2a. Comprehensive lightcurve modeling combining rotational-modulation and transits

K. F. Huber·S. Czesla·U. Wolter·J. H. M. M. Schmitt
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Abstract

We analyze the surface structure of the planet host star CoRoT-2a using a consistent model for both the `global' (i.e., rotationally modulated) lightcurve and the transit lightcurves, using data provided by the CoRoT mission. Selecting a time interval covering two stellar rotations and six transits of the planetary companion CoRoT-2b, we adopt a `strip' model of the surface to reproduce the photometric modulation inside and outside the transits simultaneously. Our reconstructions show that it is possible to achieve appropriate fits for the entire sub-interval using a low-resolution surface model with 36 strips. The surface reconstructions indicate that the brightness on the eclipsed section of the stellar surface is (6 +/- 1) % lower than the average brightness of the remaining surface. This result suggests a concentration of stellar activity in a band around the stellar equator similar to the behavior observed on the Sun.

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K. F. Huber, S. Czesla, U. Wolter, J. H. M. M. Schmitt. 2009-09-17. A planetary eclipse map of CoRoT-2a. Comprehensive lightcurve modeling combining rotational-modulation and transits. https://doi.org/10.1051/0004-6361%2F200912867

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