AAS 197, January 2001
Session 10. Low Mass Star Formation
Display, Monday, January 8, 2001, 9:30am-7:00pm, Exhibit Hall

## [10.09] Stellar Parameters of Young Stars from High Resolution NIR Spectra

G. Doppmann, D. Jaffe, R. White (Univ. TX - Austin)

Many important physical properties of young stars can be measured from high resolution spectroscopy. However, very little is known about solar type and low mass stars in the earliest stages of their evolution because these objects are faint or inaccessable at visible wavelengths due to high extinction. In order to better understand the properties of young stars, we have carried out a high resolution (R ~25,000), near infrared spectroscopic survey of young stars in Ophiuchus. This includes the complete sample of Class II'' sources brighter than K=9.0. This was done using NIRSHELL, our new high resolution, near infrared spectrograph on the 2.7m telescope at McDonald Observatory. With this data we are able to determine (1) precise radial velocities (\sigmav < 3 kms-1) from line shifts, (2) vsini rotational velocities from line widths, (3) effective temperatures from line ratios, and (4) measurements of the veiling by hot dust from the line depths. We also discovered one high flux ratio spectroscopic binary that may provide useful mass constraints on evolutionary models through further monitoring.