Scientific Inference.

Tidal Dissipation in Stars and Giant Planets

“…Ogilvie & Lin (2007) applied a similar idea to the host stars of hot Jupiters, where the stellar rotation is slow compared to the orbit, and the eccentricity is negligible; they found that, for a model based on the present Sun, a companion of more than about 3 Jupiter masses would generate waves that could break near the centre, but also noted that the threshold depends on the stellar model. More detailed calculations were made by Barker & Ogilvie (2010), who also performed numerical simulations of the breaking process. Among solar-type stars, the threshold companion mass decreases with increasing stellar mass and with increasing age.…”

“…Numerical simulations of internal gravity waves approaching the stellar centre (Barker & Ogilvie 2010;Barker 2011) show that, if the breaking amplitude is exceeded, the waves are almost completely dissipated. Angular momentum is deposited and an expanding core is formed in which material is spun up to the orbital frequency.…”

“…But the eccentricity tides in a synchronized binary star have |ω| = Ω s and can excite inertial waves in the convective zone, producing a much stronger tidal response (Ogilvie & Lin 2007). In the radiative zone of a solar-type star, the asynchronous tide can break and produce rapid orbital decay only if the planet and star are sufficiently massive, and the star sufficiently old (Barker & Ogilvie 2010;see Section 4.2). The predictions of the wave-breaking theory appear to be in fair agreement with observations (Guillot, Lin & Morel, in preparation).…”