NOAO time was granted to the c2d SIRTF Legacy Team with the echelle spectrographs at both the KPNO and CTIO 4-m telescopes in order to achieve our goal of placing SIRTF observations of protoplanetary disks in their proper evolutionary context. Observations are complete and spectra have been obtained for nearly all the sample. The resulting spectra include observations of age-diagnostic lines of Li, H&alpha, and Ca II H and K, together with radial velocities for kinematic studies and high-resolution line profiles sensitive to stellar rotation and spectroscopic binaries.

(Click on the above for a larger version)

(Click on the above for a larger version)

Examples of typical Li profiles (together with a neighboring Fe line), characteristic of very young stars are displayed in the left figure above. Li is detected in all 4 plotted spectra, but with a wide range of line widths modulated by stellar rotation and, in one case, the presence of a close and bright companion. The figure to the right above displays the wide range of line shapes measured in H&alpha. It is almost certainly the case that these illustrate an evolutionary state of the circumstellar material, as evidenced by the large line associated with a classical T Tauri star in the topmost spectrum.