Callegari, Jr., N.
Michtchenko, T. A.
Total Authors: 4
 IAG USP, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo - Brazil
 UNESP Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, BR-13506900 Rio Claro, SP - Brazil
 German Aerosp Ctr DLR, Inst Planetary Res, D-12489 Berlin - Germany
Total Affiliations: 3
Monthly Notices of the Royal Astronomical Society;
Web of Science Citations:
We investigate the spin behaviour of close-in rocky planets and the implications for their orbital evolution. Considering that the planet rotation evolves under simultaneous actions of the torque due to the equatorial deformation and the tidal torque, both raised by the central star, we analyse the possibility of temporary captures in spinorbit resonances. The results of the numerical simulations of the exact equations of motions indicate that, whenever the planet rotation is trapped in a resonant motion, the orbital decay and the eccentricity damping are faster than the ones in which the rotation follows the so-called pseudo-synchronization. Analytical results obtained through the averaged equations of the spinorbit problem show a good agreement with the numerical simulations. We apply the analysis to the cases of the recently discovered hot super-Earths Kepler-10?b, GJ 3634?b and 55 Cnc?e. The simulated dynamical history of these systems indicates the possibility of capture in several spinorbit resonances; particularly, GJ 3634?b and 55 Cnc?e can currently evolve under a non-synchronous resonant motion for suitable values of the parameters. Moreover, 55 Cnc?e may avoid a chaotic rotation behaviour by evolving towards synchronization through successive temporary resonant trappings. (AU)