2005ApJ...625L.131D

Spectroscopy of the infrared He I (10830 Å) line with NIRSPEC on Keck and CSHELL at the IRTF, and of the ultraviolet C III (977 Å) and O VI (1032 Å) emission with FUSE, reveals that the classical T Tauri star TW Hydrae exhibits P Cygni profiles, line asymmetries, and absorption indicative of a continuous, fast (∼400 km/s), hot (∼300,000 K) accelerating outflow with a mass-loss rate ∼10^–11 to 10^–12 M_☉/yr or larger. Spectra of T Tau N appear consistent with such a wind. The source of the emission and outflow seems restricted to the stars themselves. Although the mass accretion rate is an order of magnitude less for TW Hya than for T Tau, the outflow reaches higher velocities at chromospheric temperatures in TW Hya. Winds from young stellar objects may be substantially hotter and faster than previously thought.