Evolution of star-planet systems under magnetic braking and tidal interaction. (arXiv:1811.06354v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Benbakoura_M/0/1/0/all/0/1">M. Benbakoura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reville_V/0/1/0/all/0/1">V. Réville</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brun_A/0/1/0/all/0/1">A. S. Brun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Poncin_Lafitte_C/0/1/0/all/0/1">C. Le Poncin-Lafitte</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mathis_S/0/1/0/all/0/1">S. Mathis</a>
With the discovery over the last two decades of a large diversity of
exoplanetary systems, it is now of prime importance to characterize star-planet
interactions and how such systems evolve. We address this question by studying
systems formed by a solar-like star and a close-in planet. We focus on the
stellar wind spinning down the star along its main sequence phase and tidal
interaction causing orbital evolution of the systems. Despite recent
significant advances in these fields, all current models use parametric
descriptions to study at least one of these effects. Our objective is to
introduce simultaneously ab-initio prescriptions of the tidal and braking
torques, so as to improve our understanding of the underlying physics. We
develop a 1D numerical model of coplanar circular star-planet systems taking
into account stellar structural changes, wind braking and tidal interaction and
implement it in a code called ESPEM. We follow the secular evolution of the
stellar rotation assuming a bi-layer internal structure, and of the semi-major
axis of the orbit. After comparing our predictions to recent observations and
models, we perform tests to emphasize the contribution of ab-initio
prescriptions. Our secular model of stellar wind braking reproduces well the
recent observations of stellar rotation in open clusters. Our results show that
a planet can affect the rotation of its host star and that the resulting
spin-up or spin-down depends on the orbital semi-major axis and on the joint
influence of magnetic and tidal effects. The ab-initio prescription for tidal
dissipation that we used predicts fast outward migration of massive planet
orbiting fast-rotating young stars. Finally, we provide the reader with a
criterion based on the system’s characteristics that allows us to assess
whether or not the planet will undergo orbital decay due to tidal interaction.
With the discovery over the last two decades of a large diversity of
exoplanetary systems, it is now of prime importance to characterize star-planet
interactions and how such systems evolve. We address this question by studying
systems formed by a solar-like star and a close-in planet. We focus on the
stellar wind spinning down the star along its main sequence phase and tidal
interaction causing orbital evolution of the systems. Despite recent
significant advances in these fields, all current models use parametric
descriptions to study at least one of these effects. Our objective is to
introduce simultaneously ab-initio prescriptions of the tidal and braking
torques, so as to improve our understanding of the underlying physics. We
develop a 1D numerical model of coplanar circular star-planet systems taking
into account stellar structural changes, wind braking and tidal interaction and
implement it in a code called ESPEM. We follow the secular evolution of the
stellar rotation assuming a bi-layer internal structure, and of the semi-major
axis of the orbit. After comparing our predictions to recent observations and
models, we perform tests to emphasize the contribution of ab-initio
prescriptions. Our secular model of stellar wind braking reproduces well the
recent observations of stellar rotation in open clusters. Our results show that
a planet can affect the rotation of its host star and that the resulting
spin-up or spin-down depends on the orbital semi-major axis and on the joint
influence of magnetic and tidal effects. The ab-initio prescription for tidal
dissipation that we used predicts fast outward migration of massive planet
orbiting fast-rotating young stars. Finally, we provide the reader with a
criterion based on the system’s characteristics that allows us to assess
whether or not the planet will undergo orbital decay due to tidal interaction.
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