Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4. Issue 1 (19th September 2019)

• Record Type: Journal Article
• Authors: Baluev, R V; Sokov, E N; Jones, H R A; Shaidulin, V Sh; Sokova, I A; Nielsen, L D; Benni, P; Schneiter, E M; Villarreal D'Angelo, C; Fernández-Lajús, E; Di Sisto, R P; Baştürk, Ö; Bretton, M; Wunsche, A; Hentunen, V-P; Shadick, S; Jongen, Y; Kang, W; Kim, T; Pakštienė, 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;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 490:Issue 1(2019)
• Page Start: 1294
• Page End: 1312
• Publication Date: 2019-09-19
• Subjects: methods: data analysis -- methods: statistical -- techniques: photometric -- techniques: radial velocities -- surveys -- planetary systems; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz2620
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We homogeneously analyse ∼3.2 × 10 5 photometric measurements for ∼1100 transit light curves belonging to 17 exoplanet hosts. The photometric data cover 16 years (2004–2019) and include amateur and professional observations. Old archival light curves 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 non-linear transit timing variation (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 of about −7.5 ± 2.2 m s −1 yr −1, 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 homogeneous TTV sample, including 10 ground-based EXPANSION light curves 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.