A HIGH-RESOLUTION SPECTROSCOPIC STUDY OF SOUTHERN T-TAURI STARS

We present the results of a high resolution spectroscopic study of fiv e southern T Tauri stars: Sz 19, T Cha, Sz 68, Wa CrA/2, and TW Hya. T he spectra cover a wavelength range of about 50 angstrom centered on t he Na I D lines. Simultaneous UBV(RI)c photometry was also obtained. S pectral types and projected rotational velocities have been derived by comparison with reference stars. Heliocentric radial velocities of th e stars and their parent clouds have been determined. Night to night v ariability in the line profiles of T Cha, and Sz 68 was detected. The Na I D profile of Sz 68 displays at least three systems of narrow blue -shifted absorption components in the Na I D lines with only the highe st velocity one showing night to night variability in both intensity a nd width. This suggests a complex and not steady circumstellar structu re.