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

We present the results of a high resolution spectroscopic study of five southern T Tauri stars: Sz 19, T Cha, Sz 68, Wa CrA/2, and TW Hya. The spectra cover a wavelength range of about 50 angstrom centered on the Na I D lines. Simultaneous UBV(RI)c photometry was also obtained. Spectral types and projected rotational velocities have been derived by comparison with reference stars. Heliocentric radial velocities of the stars and their parent clouds have been determined. Night to night variability 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 highest velocity one showing night to night variability in both intensity and width. This suggests a complex and not steady circumstellar structure.