Volume 592, August 2016
|Number of page(s)||13|
|Section||Stellar structure and evolution|
|Published online||15 August 2016|
Spot modelling of periodic weak-line T Tauri stars observed by CoRoT in NGC 2264
1 INAF–Osservatorio Astrofisico di Catania, via S. Sofia, 78-95123 Catania, Italy
2 INAF–Osservatorio Astronomico di Palermo “G. S. Vaiana”, Piazza del Parlamento, 1 – 90134 Palermo, Italy
Received: 25 February 2016
Accepted: 17 June 2016
Context. The space telescope CoRoT has provided light curves of T Tauri stars belonging to the star-forming region of NGC 2264 with unprecedented continuity and precision in the framework of a coordinated multi-wavelength observational project.
Aims. We perform spot modelling of the optical light curves of five weak-line T Tauri stars whose variability is dominated by starspots.
Methods. We apply two-spot and evolving single-spot models in the framework of a Bayesian Markov chain Monte Carlo approach to derive the a posteriori distributions of the starspot parameters and the inclination of the star rotation axis. We focus on the rotation periods of the spots that can provide evidence for differential rotation in those stars.
Results. We find meaningful results in the case of three stars with an inclination higher than 50° and a slow variation of the light curve amplitude. The relative difference of the spot rotation periods ranges from 0.02 to 0.05 that is 3−10 times larger than the amplitude of the differential rotation found in similar stars with Doppler imaging techniques.
Conclusions. We conclude that the intrinsic starspot evolution, although very slow, has a significant impact on the determination of the differential rotation by means of our spot modelling approach. We estimate typical timescales for the evolution of the starspot pattern between ~20 and ~50 rotation periods in our stars.
Key words: stars: variables: T Tauri, Herbig Ae/Be / starspots / stars: activity / stars: rotation / techniques: photometric
© ESO, 2016
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.