Repository logo
 

Dynamical tides in exoplanetary systems containing hot Jupiters: Confronting theory and observations

Accepted version
Peer-reviewed

Change log

Authors

Chernov, SV 
Ivanov, PB 
Papaloizou, JCB 

Abstract

We study the effect of dynamical tides associated with the excitation of gravity waves in an interior radiative region of the central star on orbital evolution in observed systems containing hot Jupiters. We consider WASP-43, OGLE-TR-113, WASP-12 and WASP-18 that contain stars on the main sequence (MS). For these systems there are observational estimates regarding the rate of change of the orbital period.We also investigate Kepler-91 that contains an evolved giant star.We adopt the formalism of Ivanov et al. for calculating the orbital evolution. For the MS stars we determine expected rates of orbital evolution under different assumptions about the amount of dissipation acting on the tides, estimate the effect of stellar rotation for the two most rapidly rotating stars and compare results with observations. All cases apart from possibly WASP-43 are consistent with a regime in which gravity waves are damped during their propagation over the star. However, at present this is not definitive as observational errors are large. We find that although it is expected to apply to Kepler-91, linear radiative damping cannot explain this dissipation regime applying to MS stars. Thus, a non-linear mechanism may be needed. Kepler-91 is found to be such that the time-scale for evolution of the star is comparable to that for the orbit. This implies that significant orbital circularization may have occurred through tides acting on the star. Quasi-static tides, stellar winds, hydrodynamic drag and tides acting on the planet have likely played a minor role.

Description

Keywords

hydrodynamics, celestial mechanics., planet–star interactions, binaries: close, stars: oscillations, planetary systems

Journal Title

Monthly Notices of the Royal Astronomical Society

Conference Name

Journal ISSN

0035-8711
1365-2966

Volume Title

470

Publisher

Oxford University Press
Sponsorship
We are grateful to G. I. Ogilvie for his important remarks and suggestions. SVC and PBI were supported in part by RFBR grants 15-02-08476 and 16-02-01043, by programme 7 of the Presidium of Russian Academy of Sciences and also by Grant of the President of the Russian Federation for Support of the Leading Scientific Schools NSh-6595.2016.2.