Analysis of MOST light curves of five young stars in Taurus-Auriga and Lupus 3 Star Forming Regions

TL;DR

This study analyzes light curves of five young stars in Taurus-Auriga and Lupus 3, revealing low differential rotation, flare activity, and brightness variations, using MOST satellite data to improve understanding of stellar surface phenomena.

Contribution

The paper provides detailed light curve modeling of young stars, estimating differential rotation parameters and detecting flares, which advances knowledge of stellar activity in star-forming regions.

Findings

Low differential rotation in three WTTS stars.

Detection of three stellar flares with similar timescales.

Continuous brightness decrease in RY Tau without clear periodicity.

Abstract

Continuous photometric observations of five young stars obtained by the MOST satellite in 2009 and 2010 in the Taurus and Lupus star formation regions are presented. Using light curve modelling under the assumption of internal invariability of spots, we obtained small values of the solar-type differential-rotation parameter (k=0.0005-0.009) for three spotted weak-line T Tau stars, V410 Tau, V987 Tau and Lupus 3-14; for another spotted WTTS, Lupus 3-48, the data are consistent with a rigidly rotating surface (k=0). Three flares of similar rise (4 min 30 sec) and decay (1 h 45 min) times were detected in the light curve of Lupus 3-14. The brightness of the classical T Tau star RY Tau continuously decreased over 3 weeks of its observations with a variable modulation not showing any obvious periodic signal.