The transiting system GJ1214: high-precision defocused transit observations and a search for evidence of transit timing variation

摘要: Aims. We present 11 high-precision photometric transitobservations of the transiting super-Earth planet GJ 1214 b. Combining these data with observations from other authors, we investigate ephemeris for possible signs transit timing variations (TTVs) using a Bayesian approach. Methods. The were obtained telescope-defocusing techniques, and achieve high precision random errors in photometry as low 1 mmag per point. To possibility TTVs light curve, calculate overall probability TTV signal methods. Results. are used to determine parameters physical properties GJ 1214 system. Our results good agreement published values. Individual times mid-transit measured uncertainties 10 s, allowing us reduce uncertainty orbital period by factor two. Conclusions. A analysis reveals that it is highly improbable observed explained caused nominal habitable zone, when compared simpler alternative linear ephemeris.