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

TY - JOUR

T1 - The transiting system GJ1214

T2 - high-precision defocused transit observations and a search for evidence of transit timing variation

AU - Harpsøe, Kennet Bomann West

AU - Hardis, S.

AU - Hinse, T.C.

AU - Jørgensen, Uffe Gråe

AU - Mancini, L.

AU - Southworth, J.

AU - Alsubai, K.A.

AU - Bozza, V.

AU - Browne, P.

AU - Burgdorf, M. J.

AU - Novati, S. Calchi

AU - Dodds, P.

AU - Dominik, M.

AU - Fang, X. -S.

AU - Finet, F.

AU - Gerner, T.

AU - Gu, S. -H

AU - Hundertmark, M.

AU - Jessen-Hansen, Jens

AU - Kains, N.

AU - Kerins, E.

AU - Kjeldsen, H.

AU - Liebig, C.

AU - Lund, M.N.

AU - Lundkvist, Mia

AU - Mathiasen, M.

AU - Nesvorny, D.

AU - Nikolov, N.

AU - Penny, M. T.

AU - Proft, S.

AU - Rahvar, S.

AU - Ricci, D.

AU - Sahu, K. C.

AU - Scarpetta, G.

AU - Schaefer, S.

AU - Schoenebeck, F.

AU - Snodgrass, C.

AU - Skottfelt, Jesper Fælling

AU - Surdej, J.

AU - Tregloan-Reed, J.

AU - Wertz, O.

PY - 2012

Y1 - 2012

N2 - 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.

AB - 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.

U2 - 10.1051/0004-6361/201219996

DO - 10.1051/0004-6361/201219996

M3 - Journal article

SN - 0004-6361

VL - 549

JO - Astronomy and Astrophysics Supplement Series

JF - Astronomy and Astrophysics Supplement Series

M1 - A10

ER -