[Previous] | [Session 78] | [Next]
G. Torres (CfA), R. Neuhäuser (MPE, Garching), D.W. Latham, R.P. Stefanik (CfA)
For the past 2.5 years we have been monitoring a group of stars in the TW~Hya region with the Center for Astrophysics echelle spectrographs. The sample consists of optically discovered T~Tauri stars and also X-ray selected candidate members of the young association. Our main goals are to measure the radial velocities in order to study the kinematic membership, and also to look for spectroscopic binaries. In the process we also determine the effective temperatures and projected rotational velocities. Our radial velocity measurements strongly suggest that many of these stars are kinematically associated, in agreement with their strong Lithium \lambda6708Å~absorption. Five or six of the objects have variable radial velocities, and at least two are double-lined, although most of these are probably not members of the association based on their radial velocities. We present spectroscopic orbital solutions for two of the systems, one of which is triple.