Determination of Kinematic Distances of Pre-Main Sequence Stars in Lupus

The problem of the determination of distances has always played a central role in astronomy. However, little recent progress has been made in the distance determination of faint young stellar objects such as pre-main sequence (PMS) stars. A precise determination of distances is required to accurately determine the main physical parameters of stars (luminosity, temperature, mass and age) and to trace the evolutionary tracks of young stars. The procedure that we use here to derive individual parallaxes is based on the convergent point strategy which makes full use of the directly observed data: position, proper motion and radial velocity. %Z Ducourant, C., et al. 2005, A&A, 438, 769 Jones, D. H. P. 1971, MNRAS, 152, 231 Bertout, C., & Genova, F. 2006, A&A, 460, 49