The GAPS Programme with HARPS-N@TNG XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets
Creators: name: Bonomo, A. S.
name: Desidera, S.
name: Benatti, S.
name: Borsa, F.
name: Crespi, S.
name: Damasso, M.
name: Lanza, A. F.
name: Sozzetti, A.
name: Lodato, G.
name: Marzari, F.
name: Boccato, C.
name: Claudi, R. U.
name: Cosentino, R.
name: Covino, E.
name: Gratton, R.
name: Maggio, A.
name: Micela, G.
name: Molinari, E.
name: Pagano, I.
name: Piotto, G.
name: Poretti, E.
name: Smareglia, R.
name: Affer, L.
name: Biazzo, K.
name: Bignamini, A.
name: Esposito, M.
name: Giacobbe, P.
name: Hébrard, G.
name: Malavolta, L.
name: Maldonado, J.
name: Mancini, L.
name: Fiorenzano, A. Martinez
name: Masiero, S.
name: Nascimbeni, V.
name: Pedani, M.
name: Rainer, M.
name: Scandariato, G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We carried out a Bayesian homogeneous determination of the orbital parameters of 231 transiting giant planets (TGPs) that are alone or have distant companions; we employed DE-MCMC methods to analyse radial-velocity (RV) data from the literature and 782 new high-accuracy RVs obtained with the HARPS-N spectrograph for 45 systems over 3 years. Our work yields the largest sample of systems with a transiting giant exoplanet and coherently determined orbital, planetary, and stellar parameters. We found that the orbital parameters of TGPs in non-compact planetary systems are clearly shaped by tides raised by their host stars. Indeed, the most eccentric planets have relatively large orbital separations and/or high mass ratios, as expected from the equilibrium tide theory. This feature would be the outcome of high-eccentricity migration (HEM). The distribution of $α=a/a_R$, where $a$ and $a_R$ are the semi-major axis and the Roche limit, for well-determined circular orbits peaks at 2.5; this also agrees with expectations from the HEM. The few planets of our sample with circular orbits and $α&gt;5$ values may have migrated through disc-planet interactions instead of HEM. By comparing circularisation times with stellar ages, we found that hot Jupiters with $a &lt; 0.05$ au have modified tidal quality factors $10^{5} &lt; Q'_p &lt; 10^{9}$, and that stellar $Q'_s &gt; 10^{6}-10^{7}$ are required to explain the presence of eccentric planets at the same orbital distance. As a by-product of our analysis, we detected a non-zero eccentricity for HAT-P-29; we determined that five planets that were previously regarded to have hints of non-zero eccentricity have circular orbits or undetermined eccentricities; we unveiled curvatures caused by distant companions in the RV time series of HAT-P-2, HAT-P-22, and HAT-P-29; and we revised the planetary parameters of CoRoT-1b.
description: 44 pages (16 pages of main text and figures), 11 figures, 5 longtables, published in Astronomy and Astrophysics, Volume 602, A107 (2017). Tables with new HARPS-N and TRES radial-velocity data (Tables 1 and 2), stellar parameters (Table 7), orbital parameters and RV jitter (Table 8), and planet physical parameters (Table 9) are available as ancillary files (sidebar on the right)