Chasing the Tides: Searching for Orbital Decay Signatures in Transit Timing Data and Tidal Models for 20 Hot Jupiters

Abstract In this work, we present a transit timing variation analysis for 20 hot Jupiter systems, which we interpret with theoretical tidal dissipation models. For the majority of the sample, we conclude that a constant orbital period model represents the timing data best. Only WASP-12 b, TrES-1 b and WASP-121 b exhibit a changing orbital period, according to the most up-to-date results. We updated the orbital decay rate of WASP-12 b to P ̇ = − 29.4 ± 4.0 ms yr − 1 and the corresponding stellar tidal quality factor to Q ∗ ′ = 1.72 ± 0.18 × 1 0 5 . For TrES-1 b, the median quadratic model suggests a period decrease at a rate of −14.9 ± 0.6 ms yr −1 , but the corresponding Q ∗ ′ = 570 ± 60 does not agree with the theoretical estimates, which suggest Q ∗ ′ ∼ 1 0 6 due to internal gravity wave dissipation. Lastly, WASP-121 b exhibits orbital growth at a rate of 15.1 ± 0.8 ms yr −1 , and theoretical results support outward migration due to strong inertial wave dissipation.