Accretion and wind modulation in T Tauri star RY Tau: a planet at 0.2 AU?

Abstract

Spectral and photometric monitoring of CTTS RY Tau in 2013–2021 revealed variations in the H α and Na i D lines atradial velocities of infall (accretion) and outflow (wind) with a period of about 22 days. The Na i D absorption in theinfalling and outflowing gas changes in anti-phase: an increase in the density of infalling gas is accompanied by a decreasein the wind density, and vice versa. The fluctuations remain coherent for several years of observation. We assume that theobserved effect may be due to processes at the disk-magnetosphere boundary in MHD propeller mode. The stability of theoscillation phase indicates the possible presence of a massive planet, causing azimuthal asymmetry of the accretion andwind flows. If the observed period (22 days) is Keplerian, then the planet is located at a distance of 0.2 AU and moves withan orbital velocity of 100 km s −1 .