AAO Colloquium.


Monday 10 February 2003

11am AAO Conference Room

Probing the circumstellar structure of Pre-Main Sequence Stars

Jorick Vink
Imperial College

We present H_alpha spectropolarimetry observations of T Tauri and Herbig Ae/Be stars. The technique enables us to probe the circumstellar structure around these different types of Pre-Main Sequence (PMS) objects at small scales. By studying PMS stars over a wide spectral range, we explore whether physics of known importance for lower mass (T Tauri) stars, such as the presence of accretion discs, is also relevant for earlier type PMS objects. Our data caries vital information on the small scale structure that is required to answer the fundamental question of whether more massive stars form in a manner analogous to T Tauri stars, i.e. by accretion, or whether they form in an entirely different mode (stellar collisions).