Volume 489, Number 3, October III 2008
|Page(s)||L53 - L56|
|Published online||11 September 2008|
Letter to the Editor
Lithium depletion and the rotational history of exoplanet host stars
Laboratoire d'Astrophysique, Observatoire de Grenoble, Université J. Fourier, CNRS, UMR 5571, BP 53, 38041 Grenoble Cedex 9, France e-mail: firstname.lastname@example.org
Accepted: 26 August 2008
Context. It has been reported that exoplanet host stars are lithium depleted compared to solar-type stars without detected massive planets.
Aims. We investigate whether enhanced lithium depletion in exoplanet host stars may result from their rotational history.
Methods. We have developed rotational evolution models for slow and fast solar-type rotators from the pre-main sequence (PMS) to the age of the Sun and compare them to the distribution of rotational periods observed for solar-type stars between 1 Myr and 5 Gyr.
Results. We show that slow rotators develop a high degree of differential rotation between the radiative core and the convective envelope, while fast rotators evolve with little core-envelope decoupling. We suggest that strong differential rotation at the base of the convective envelope is responsible for enhanced lithium depletion in slow rotators.
Conclusions. We conclude that lithium-depleted exoplanet host stars were slow rotators on the zero-age main sequence (ZAMS) and argue that slow rotation results from a long lasting star-disk interaction during the PMS. Altogether, this suggests that long-lived disks (≥5 Myr) may be a necessary condition for massive planet formation/migration.
Key words: planetary systems: formation / stars: rotation / stars: abundances / stars: pre-main sequence / accretion, accretion disks / hydrodynamics
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.