Polarimetric and spectroscopic study of the weak-emission T Tauri star V 410 Tauri

Abstract

Results of the polarimetric and spectroscopic observations of the weak emission T Tauri star V 410 Tau are presented. The linear polarization and position angle are found to show variability with a period corresponding to the star's rotational period. It is also found that the polarization reaches a maximum near the light minimum. Modelling of the V and R light curves shows that two adjacent spots, occupying a total fractional area of 0.23 and with a temperature 750 K cooler than the photosphere, could account for the observed light variability. We attribute the periodic variability in linear polarization to the variable illumination of an optically thin circumstellar envelope by the rotating spotted star. The Hα line is found to vary from shallow absorption to emission with the maximum emission strength at the minimum light, and vice versa. The \ion{Li} I 6708 Angstroms absorption equivalent width, which is consistent with that of the other T Tauri stars, is found to show no appreciable variation with the photometric phase.