Volume 506, Number 1, October IV 2009
The CoRoT space mission: early results
|Page(s)||263 - 268|
|Published online||28 July 2009|
On the differential rotation of CoRoT-2a*
Astrophysikalisches Institut Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany e-mail: HEFroehlich@aip.de
2 Thüringer Landessternwarte Tautenburg, Karl-Schwarzschild-Observatorium (TLS), Sternwarte 5, 07778 Tautenburg, Germany e-mail: email@example.com
Accepted: 15 July 2009
We apply a robust spot model to fit the light curve of CoRoT-2a. The spots are assumed to be long-living and each has its own rotation period. A model with three circular spots reproduces the basic features of the longitude-time spot coverage map. One of the spots exhibits a noticeably lower rotational frequency than the other two. From the rotational frequencies of the three dark features we infer a differential rotation of above 0.11 rad/d, in rough agreement with theoretical models. Mean field models of angular momentum transport by convection and meridional flow lead to an equatorial rotational frequency that exceeds that of the poles by 0.09 rad/d. The spot decay corresponds to a turbulent magnetic diffusivity of cm2/s.
Key words: stars: activity / stars: individual: CoRoT-2a / stars: interiors / stars: late-type / stars: rotation / starspots
© ESO, 2009
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.