Rotation of T Tauri Stars Revisited

L. J. R. Machado1, M. T. V. T. Lago1,2, J. J. F. G. A. Lima1,2,
J. F. S. Gameiro1,2, A. M. G. P. S. Pedrosa1

1 Centro de Astrofísica da Universidade do Porto
2 Departamento de Matemática Aplicada, Faculdade de Ciências da Universidade do Porto


A review of the rotation of T Tauri stars is presented. From a bibliographic survey it is shown that T Tauri stars are usually slow rotators. More than half of the stars in the sample have (v sin i) < 25 km/s, this larger sample confirming the unexpected results obtained by Vogel and Kuhi (1981). Moreover a critical study of the precision of the various types of observations is also included.

The histogram for the photometric periods of rotation is bimodal, with a peak at approximately 3 days and another around 8 days. A possible explanation to this fact could be the separation of T Tauri stars in the two classes: Classical T Tauri Stars (CTTS) and Weak-line T Tauri Stars (WTTS). Since CTTS show an infrared excess they might be associated with a circumstellar disk which prevents them to spin up, while WTTS lacking such a disk rotate faster.

The analysis of (v sin i) and rotation period as a function of spectral type is also presented.


Back to the Programme?