Wind Dynamics and Circumstellar Extinction Variations in the T Tauri Star RY Tau

TL;DR

This study investigates how wind interactions influence brightness variations in the T Tauri star RY Tau, revealing a correlation between stellar brightness and wind velocity caused by dust in the circumstellar disk wind.

Contribution

It provides the first evidence of a correlation between stellar brightness and wind velocity in RY Tau, linking brightness variations to dust wind dynamics near the star.

Findings

Brightness variations are caused by extinction in the dusty disk wind.

A correlation between wind velocity and stellar brightness was observed.

Circumstellar extinction variations are linked to magnetospheric changes.

Abstract

The wind interaction with the dusty environment of the classical T Tauri star RY Tau has been investigated. During two seasons of 2013-2015 we carried out a spectroscopic and photometric (BVR) monitoring of the star. A correlation between the stellar brightness and the radial velocity of the wind determined from the H-alpha and Na D line profiles has been found for the first time. The irregular stellar brightness variations are shown to be caused by extinction in a dusty disk wind at a distance of about 0.2 AU from the star. We suppose, that variations of the circumstellar extinction results from cyclic rearrangements of the stellar magnetosphere and coronal mass ejections, which affect the dusty disk wind near the inner boundary of the circumstellar disk.