Analysis of variability of TW Hya as observed by MOST and ASAS in 2009

Abstract

As a continuation of our previous studies in 2007 and 2008, new photometric observations of the T Tauri star TW Hya obtained by the MOST satellite and the ASAS project over 40 days in 2009 with temporal resolution of 0.2 days are presented. A wavelet analysis of the combined MOST-ASAS data provides a rich picture of coherent, intermittent, variable-period oscillations, similarly as discovered in the 2008 data. The periods (1.3 - 10 days) and systematic period shortening on time scales of weeks can be interpreted within the model of magneto-rotationally controlled accretion processes in the inner accretion disk around the star. Within this model and depending on the assumed visibility of plasma parcels causing the oscillations, the observed shortest-period oscillation period may indicate the stellar rotation period of 1.3 or 2.6 d, synchronized with the disk at 4.5 or 7.1 solar radii, respectively.

Accepted to MNRAS

References in corpus (7)

• Magnetospheric accretion-ejection processes in the classical T Tauri star AA
• Magnetospheric accretion on the T Tauri star BP Tauri
• Lithium Depletion of Nearby Young Stellar Associations
• Accretion Disks around Young Stars: Lifetimes, Disk Locking and Variability
• Photometric variability of the T Tauri star TW Hya on time scales of hours to years
• The absence of sub-minute periodicity in classical T Tauri stars
• Analysis of the MOST light curve of the heavily spotted K2IV component of the single-line spectroscopic binary II Pegasi

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• TW Hya: Spectral Variability, X-Rays, and Accretion Diagnostics
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• Photometric variability of TW~Hya from seconds to years as seen from space and the ground in 2013-2017
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• Periodic Eclipses of the Young Star PDS 110 Discovered with WASP and KELT Photometry
• Stable and unstable accretion in the classical T Tauri stars IM Lup and RU Lup as observed by MOST
• Photometric variability in FU Ori and Z CMa as observed by MOST
• Kinematics of Ionized Gas at 0.01 AU of TW Hya
• Insights into the inner regions of the FU Orionis disc
• A stable quasi-periodic 4.18 d oscillation and mysterious occultations in the 2011 MOST light curve of TWHya
• The GRAVITY young stellar object survey XIV : Investigating the magnetospheric accretion-ejection processes in S CrA N
• Photometric variability of the pre-main sequence stars towards the Sh 2-190 region