Results of the ROTOR-program. II. The long-term photometric variability of weak-line T Tauri stars

Abstract

T Tauri stars exhibit variability on all timescales, whose origin is still debated. On WTTS the variability is fairly simple and attributed to long-lived, ubiquitous cool spots. We investigate the long term variability of WTTS, extending up to 20 years in some cases, characterize it statistically and discuss its implications for our understanding of these stars. We have obtained a unique, homogeneous database of photometric measurements for WTTS extending up to 20 years. It contains more than 9 000 UBV R observations of 48 WTTS. All the data were collected at Mount Maidanak Observatory (Uzbekistan) and they constitute the longest homogeneous record of accurate WTTS photometry ever assembled. Definitive rotation periods for 35 of the 48 stars are obtained. Phased light curves over 5 to 20 seasons are now available for analysis. Light curve shapes, amplitudes and colour variations are obtained for this sample and various behaviors exhibited, discussed and interpreted. Our main conclusion is that most WTTS have very stable long term variability with relatively small changes of amplitude or mean light level. The long term variability seen reflects modulation in the cold spot distributions. Photometric periods are stable over many years, and the phase of minimum light can be stable as well for several years. On the long term, spot properties do change in subtle ways, leading to secular variations in the shape and amplitudes of the light curves.

References in corpus (2)

• Results of the ROTOR-program. I. The long-term photometric variability of classical T Tauri stars
• The Monitor project: JW 380 -- a 0.26, 0.15 Msol pre main sequence eclipsing binary in the Orion Nebula Cluster

Cited by in corpus (19)

• Placing the spotted T Tauri star LkCa 4 on an HR diagram
• Temperaments of young stars: Rapid mass-accretion rate changes in T Tauri and Herbig Ae stars
• CSI 2264: Investigating rotation and its connection with disk accretion in the young open cluster NGC 2264
• A hot Jupiter around the very active weak-line T Tauri star TAP 26
• A Young Planet Search in Visible and IR Light: DN Tau, V836 Tau, and V827 Tau
• Modelling the magnetic activity & filtering radial velocity curves of young Suns: the weak-line T Tauri star LkCa 4
• The hot Jupiter of the magnetically-active weak-line T Tauri star V830 Tau
• Deep near-IR variability survey of pre-main-sequence stars in Rho Ophiuchi
• Accretion and Magnetic Reconnection in the Classical T Tauri Binary DQ Tau
• Accretion discs as regulators of stellar angular momentum evolution in the ONC and Taurus-Auriga
• Rotation Effects in Classical T Tauri Stars
• CO Fundamental Emission from V836 Tau
• Star-disk interactions in multi-band photometric monitoring of the classical T Tauri star GI Tau
• A Transient Transit Signature Associated with the Young Star RIK-210
• Very Low-Mass Stars and Brown Dwarfs in Upper Scorpius using Gaia DR1: Mass Function, Disks and Kinematics
• The model of dynamo with small number of modes and magnetic activity of T Tauri stars
• CoRoT 223992193: Investigating the variability in a low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk
• Multi-Color Simultaneous Photometry of the T-Tauri Star Having A Planetary Candidate CVSO 30
• Magnetically Active Stars in Taurus-Auriga: Evolutionary Status