Effect of the stellar spin history on the tidal evolution of close-in planets
MATT, Sean P.
Astrophysique Interprétation Modélisation [AIM (UMR7158 / UMR_E_9005 / UM_112)]
NASA Ames Research Center [ARC]
< Réduire
Astrophysique Interprétation Modélisation [AIM (UMR7158 / UMR_E_9005 / UM_112)]
NASA Ames Research Center [ARC]
Langue
en
Article de revue
Ce document a été publié dans
Astronomy and Astrophysics - A&A. 2012, vol. 544, p. A124
EDP Sciences
Résumé en anglais
We investigate how the evolution of the stellar spin rate affects, and is affected by, planets in close orbits, via star-planet tidal interactions. To do this, we used a standard equilibrium tidal model to compute the ...Lire la suite >
We investigate how the evolution of the stellar spin rate affects, and is affected by, planets in close orbits, via star-planet tidal interactions. To do this, we used a standard equilibrium tidal model to compute the orbital evolution of single planets orbiting both Sun-like stars and 0.1 M\odot M-dwarfs. We tested two stellar spin evolution profiles, one with fast initial rotation (P=1.2 day) and one with slow initial rotation (P=8 day). We tested the effect of varying the stellar and planetary dissipation and the planet's mass and initial orbital radius. Conclusions: Tidal evolution allows to differentiate the early behaviors of extremely close-in planets orbiting either a rapidly rotating star or a slowly rotating star. The early spin-up of the star allows the close-in planets around fast rotators to survive the early evolution. For planets around M-dwarfs, surviving the early evolution means surviving on Gyr timescales whereas for Sun-like stars the spin-down brings about late mergers of Jupiter planets. In light of this study, we can say that differentiating between one spin evolution from another given the present position of planets can be very tricky. Unless we can observe some markers of former evolution it is nearly impossible to distinguish the two very different spin profiles, let alone intermediate spin profiles. Though some conclusions can still be drawn from statistical distributions of planets around fully convective M-dwarfs. However, if the tidal evolution brings about a merger late in its history it can also entail a noticeable acceleration of the star in late ages, so that it is possible to have old stars that spin rapidly. This raises the question of better constraining the age of stars.< Réduire
Mots clés en anglais
Solar and Stellar Astrophysics
Astrophysics
Earth and Planetary Astrophysics
Origine
Importé de halUnités de recherche