Spot modelling of periodic weak-line T Tauri stars observed by CoRoT in NGC 2264

Abstract

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. We perform spot modelling of the optical light curves of five weak-line T Tauri stars whose variability is dominated by starspots. We apply two-spot and evolving single spot models in the framework of a Bayesian Monte Carlo Markov Chain approach to derive the a posteriori distribution 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. We find meaningful results in the case of three stars with an inclination higher than 50 deg 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. 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 about 20 and 50 rotation periods in our stars.

12 pages, 13 figures, 11 tables; research note accepted by Astronomy and Astrophysics

References in corpus (10)

• Mapping accretion and its variability in the young open cluster NGC 2264: a study based on u-band photometry
• Results of the ROTOR-program. II. The long-term photometric variability of weak-line T Tauri stars
• CSI 2264: Probing the inner disks of AA Tau-like systems in NGC 2264
• UV variability and accretion dynamics in the young open cluster NGC 2264
• Modelling the magnetic activity & filtering radial velocity curves of young Suns: the weak-line T Tauri star LkCa 4
• Magnetic activity and hot Jupiters of young Suns: the weak-line T Tauri stars V819 Tau and V830 Tau
• Comparing different approaches to model the rotational modulation of the Sun as a star
• On Sunspot and Starspot Lifetimes
• The differential rotation of epsilon Eri from MOST data
• Magnetic activity in the photosphere of CoRoT-Exo-2a. Active longitudes and short-term spot cycle in a young Sun-like star

Cited by in corpus (10)

• Asteroseismology of solar-type stars
• Quantifying Variability of YSOs in the Mid-IR Over Six Years with NEOWISE
• GIARPS High-resolution Observations of T Tauri stars (GHOsT). IV. Accretion properties of the Taurus-Auriga young association
• WIde Separation Planets In Time (WISPIT): A Gap-clearing Planet in a Multi-ringed Disk around the Young Solar-type Star WISPIT 2
• Activity cycles in members of young loose stellar associations
• The effect of spots on the luminosity spread of the Pleiades
• Starspot evolution, Differential Rotation and Correlation between Chromospheric and Photospheric Activities on Kepler-411
• Robo-AO Discovery and Basic Characterization of Wide Multiple Star Systems in the Pleiades, Praesepe, and NGC 2264 Clusters
• An investigation of the magnetic activity of HD 134319 based on TESS photometry and ground-based spectroscopy
• Inactive longitude and superflare in the active single-lined pre-main sequence binary V2279 Cyg