A study of transiting extrasolar planets, Markus Rabus (DAA-PUC)

Planets showing transits during their orbit are so far the best studied exoplanets. A transit occurs when the orbit of an exoplanet is oriented in such a way that during an orbital phase (transit phase) the planet occults part of the stellar surface. This occultation, when photometrically observed, will cause a decrease in the observable flux during transit. After a transiting exoplanet around a star has been confirmed, one can start to further characterize the system. In this talk I will start presenting photometric infrared observations done for primary transit and secondary eclipse phases. High precision photometric infrared observations of the primary transit can help to constrain the presence of possible additional bodies in the system, whereas secondary eclipse observations indicate the light from the planet, which is composed of emitted and reflected light. Next, I will demonstrate that star spots and a second transiting planet, when aligned favorably, can leave in the light curve a flux increase during transit. Based on multi-color photometry, one may be able to distinguish the nature of this flux increase, i. e. if it is caused by a star spot or another transiting planet. Finally I will show that bodies, which are unseen in the light curve, can be detected  through their gravitational influence. If there is no third body present in a transiting exoplanetary system, then the transits of the exoplanet will occur with strict periodicity. By measuring a deviation from this periodicity it is possible to detect or at least to put constraints on the presence of additional objects. The above investigations show the rich information obtained from observations of transiting exoplanets.