Measuring the orbit shrinkage rate of hot Jupiters due to tides

Context. A tidal interaction between a star and close-in exoplanet leads to shrinkage of the planetary orbit eventual dis- ruption planet. Measuring orbits will allow for quality parameter ( Q ★ ′ ) be measured, which is an important obtain information about stellar interiors. Aims. We analyse data from Transiting Exoplanet Survey Satellite (TESS) two targets known host hot Jupiters, have significant available are expected fast decay: WASP-18 WASP-19. aim measure current limits on orbital period variation provide new constrains our targets. Methods. modelled transit shape using all TESS observations fitted individual times each tran- sit. used previously published together with results fit models, constant model, quadratic decay Markov chain Monte Carlo (MCMC) algorithms. Results. both improve precision planet parameters newest TESS. find change rates (−0.11 ± 0.21) × 10 −10 WASP-18b (−0.35 0.22) WASP-19b we do not evidence in these lower (1.42 0.34) 7 (1.26 0.10) 6 WASP-19, corresponding upper rate −0.45 −0.71 , respectively, 95% confidence level. compare other relevant studies. Conclusions. that appears smaller than measured WASP-12b. show minimum value orders magnitude higher WASP-12, while WASP-19 has one order higher, consistent similar Further required constrain