The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation
Abstract
Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods: The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods. Results: The observations are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period by a factor of two. Conclusions: A Bayesian analysis reveals that it is highly improbable that the observed transit times is explained by TTV, when compared with the simpler alternative of a linear ephemeris.
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Cite
@article{arxiv.1207.3064,
title = {The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation},
author = {K. B. W. Harpsøe and S. Hardis and T. C. Hinse and U. G. Jørgensen and L. Mancini and J. Southworth and K. A. Alsubai and V. Bozza and P. Browne and M. J. Burgdorf and S. Calchi Novati and P. Dodds and M. Dominik and X. -S. Fang and F. Finet and T. Gerner and S. -H. Gu and M. Hundertmark and N. Kains and E. Kerins and H. Kjeldsen and C. Liebig and M. N. Lund and M. Lundkvist and M. Mathiasen and D. Nesvorný and N. Nikolov and M. T. Penny and S. Proft and S. Rahvar and D. Ricci and K. C. Sahu and G. Scarpetta and S. Schäfer and F. Schönebeck and C. Snodgrass and J. Skottfelt and J. Surdej and J. Tregloan-Reed and O. Wertz},
journal= {arXiv preprint arXiv:1207.3064},
year = {2012}
}
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