http://arxiv.org/abs/1907.10575
We aim to study the orbital and rotational evolution of binary system, formed by a rocky planet and its host star, near spin-orbit resonances, considering the tidal dissipation within both bodies in order to characterize the dynamical evolution with respect to the main features of the tidal evolution, i.e. synchronization, circularization and planarization. To that end, we make use the equations of motions which give the time evolution of the semi-major axis, the eccentricity and the inclination of the star’s orbit as seen from the planet and that of the planet as seen from the star due to both the tidal and the permanent-triaxiality-caused disturbing potentials. They also give the the angular accelerations caused by the torque and the triaxiality-caused torques which. We found that at least for the parameters and the initial conditions explored, the time span of the numerical integrations performed and for the cases studied the orbital evolution is independent of the rotational initial conditions. Instead they depend strongly on the rheological parameters. We have also observed that both the rotational and orbital evolution can be completely described in terms of the secular evolution due to the tidal interaction solely, at least qualitatively, including the estimation of characteristic time scales of orbital evolution. Concerning this last aspect, we found that as the time scale of orbital decay is longer than the others, we expect that the orbits will be circularized and planarizated before the planets arrive to the Roche limit. We have also found that the dynamical evolution has an unexpected consequence on the host star’s rotation, causing that it has to decrease its rotation angular momentum in order to the total angular momentum of the system is conserved.
S. Luna, M. Melita and H. Navone
Thu, 25 Jul 19
53/72
Comments: 25 pages, 9 figures, 3 tables. Preprint to submit to A&A journal