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Description
The transiting extrasolar planet WASP-12b was found to be the one of the most intensely irradiated exoplanets. It is unexpectedly bloated and is losing mass which may accrete into the host star. Our aim was to refine parameters of this intriguing system and search for signs of transit timing variations. We gathered high-precision light curves of two transits of WASP-12b. Assuming various limb darkening laws, we generated best-fitting models and redetermined parameters of the system. Error estimates were derived by the prayer bread method and Monte Carlo simulations. System's parameters obtained by us were found to agree with previous studies within one sigma. Use of the non-linear limb darkening laws resulted in the best- fitting models. With two new mid-transit times, the ephemeris was refined to BJD_TDB_=(2454508.97682+/-0.00020)+(1.09142245+/-0.00000033)E. Interestingly, indications for transit timing variation were detected at the level of 3.4 sigma. This signal could be induced by an additional planet in the system. Simplified numerical simulations showed that a perturber could be a terrestrial-type planet if both planets are in a low-order orbital resonance. However, we emphasise that further observations are needed to confirm variation and to put constraints on properties of the perturber.
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