Study of Spectroscopic Variability of T Tau Stars

T. PALMA, L. GRAMAJO, J. F. GONZÁLEZ, M. GÓMEZ

Córdoba

Congreso; X Reunion Regional Latinoamericana de Astronomia; 2001

IAU

We present results of a spectroscopic variability analysis of the four T Tauri stars RY Lup, T Cha, SR-9 and Wa CrA. All of them showed to be radial velocity variables with amplitudes in the range 2-10km/s. Observations of RY Lup show good agreement with the variable circumstellar extinction model. For the remaining stars we found that spots model was the best representative of their behavior. However, the observed radial velocity variations can also be explained by the presence of a secondary binary companion, for which we estimate a lower limit of 20-50 Jupiter masses. We cannot confirm any particular explanation of the observed variability because of the small number of observations available at present (about 10-20 spectra per object). Further observations would be necessary in order to decide which model fits better the obervational data.