Tidal migration of hot Jupiters: introducing the impact of gravity wave dissipation

We study the migration of hot Jupiters orbiting solar-type pre-main sequence and main-sequence stars under the effect of tidal dissipation. The explored range of stellar mass extends from 0.6 to 1.3 M-circle dot. We apply recently developed prescriptions that allow us to explore the orbital evolution over the wide parameter space. Three types of tides are considered: equilibrium tide, inertial waves, and gravity waves. We combine the results of our simulations with the observed distribution of stellar and planetary parameters to evaluate the infall rate of hot Jupiters in the Milky Way Galaxy. In particular, we find that, for 11-21 percent of the initial hot Jupiter population, coalescence occurs before the host star's main sequence termination. If the planet is massive enough, such an event can potentially be accompanied by a powerful transient detectable with new facilities. Orbital decay by itself can be observed through transit-timing variation. However, the obtained coalescence rate in the Galaxy is too low (340-650 events per million years) to make positive predictions about the observational possibility. Potentially identifiable decaying systems formed by a star corresponding to a given mass interval might be too rare to be detected with the modern space telescopes, like TESS, within a 10-yr baseline. At the same time, the forthcoming missions, like PLATO, look more promising in this regard.

Automated summary

The study indicates that hot Jupiters may merge before the termination of their host stars' main sequence, potentially accompanied by transient events. However, the coalescence rate in the Galaxy is relatively low, making positive predictions about observational possibilities difficult. Identifiable decaying systems formed by stars corresponding to a given mass interval may be too rare to be detected within a 10-yr baseline of modern space telescopes.