Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

BALUEV, R V; SOKOV, E N; JONES, H R A; SHAIDULIN, V SH; SOKOVA, I A; NIELSEN, L D; BENNI, P; SCHNEITER, E M; D?ANGELO, C VILLARREAL; FERNÁNDEZ-LAJÚS, E; DI SISTO, R P; BA?TÜRK, Ö; BRETTON, M; WUNSCHE, A; HENTUNEN, V-P; SHADICK, S; JONGEN, Y; KANG, W; KIM, T; PAK?TIEN?, E; QVAM, J K T; KNIGHT, C R; GUERRA, P; MARCHINI, A; SALVAGGIO, F; PAPINI, R; EVANS, P; SALISBURY, M; GARCIA, F; MOLINA, D; GARLITZ, J; ESSEIVA, N; OGMEN, Y; KARAVAEV, YU; RUSOV, S; IBRAHIMOV, M A; KARIMOV, R G

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019 vol. 490 p. 1294 - 1312

0035-8711

We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004?2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions.