  RY Tau is a rapidly rotating Classical T Tauri star observed close to
edge-on. The combination of new HST/STIS observations obtained in 2001 with
HST/GHRS Archive data from 1993 has allowed us to get, for the first time,
information on the thermal structure and the velocity law of the wind. The
repeated observations of the Si III] and C III] lines show a lack of changes
with time in the blue side of the profile(dominated by the wind contribution).
Very high temperature plasma (log Te = 4.8) is detected at densities of 9.5<log
ne(cm3)< 10.2 associated with the wind. The emitting volumes are about
(0.35Ro)^3 suggesting a stellar origin. The wind kinematics derived from the
profiles (Si III], C III] and [O II]) does not satisfy the theoretical
predictions of MHD centrifugally driven disk winds. The profiles' asymmetry,
large velocity dispersions and small variability as well as the small emitting
volumes are best explained if the wind is produced by the contribution of
several outflows from atmospheric open field structures as those observed in
the Sun.
