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

Harpsøe, K. B. W ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1051/0004-6361/201219996
  3. Publisher: 2012
  4. Abstract:
  5. 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 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 1 mmag 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 GJ≠1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10 s, 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 caused by a planet in the nominal habitable zone, when compared with the simpler alternative of a linear ephemeris
  6. Keywords:
  7. Methods: observational ; Methods: statistical ; Planetary systems ; Stars: individual: GJ1214 ; Techniques: photometric ; Methods:observational ; Methods:statistical ; Planetary system ; Stars: individual ; Astronomy ; Bayesian networks ; Earth (planet) ; Photometry
  8. Source: Astronomy and Astrophysics ; Volume 549 , 2012 ; 00046361 (ISSN)
  9. URL: http://www.aanda.org/articles/aa/abs/2013/01/aa19996-12/aa19996-12.html