HIgh-precision transit timing of exoplanet WASP-12b
Final Report Abstract
The transiting extrasolar planet WASP-12 b was found to be one of the most intensely irradiated exoplanets. It is unexpectedly bloated and is losing mass that may accrete into the host star. Our aim was to refine the parameters of this intriguing system and search for signs of transit timing variations. We gathered high-precision lightcurves for two transits of WASP-12 b. Assuming various limb-darkening laws, we generated best-fitting models and re-determined the parameters of the system. Error estimates were derived by the prayer-bead method and Monte Carlo simulations. System parameters obtained by us are found to agree with previous studies within one sigma. Use of the non-linear limb-darkening laws results in the best-fitting models. With two new mid-transit times, the ephemeris was refined to BJDtdb = (2454508.97682 ± 0.00020) + (1.09142245 ± 0.00000033)E. Interestingly, indications of transit timing variation are detected at the level of 3.4 sigma. This signal can be induced by an additional planet in the system. Simplified numerical simulations show that a perturber could be a terrestrial-type planet if both planets are in a low-order orbital resonance. However, we emphasize that further observations are needed to confirm variation and to constrain properties of the perturber.
Publications
- High-precision photometry of WASP-12 b transits, 2011, A&A 528, 65
G. Maciejewski, R. Errmann, S. Raetz, M. Seeliger, I. Spaleniak, R. Neuhäuser
- Is the orbital period of WASP-12 b constant? 2nd CoRoT Symposium, Marseille, 14-17 June 2011
Maciejewski G., Dimitrov D., Ohlert J., Neuhäuser R., Raetz S., Seeliger M., Errmann R.
