First Results from a STIS Survey of Close Pre-Main-Sequence Binaries in Taurus

Kenyon, S. J. (CfA) and Hartigan, P. (Rice)

We describe preliminary results of an HST survey of pre-main sequence binary stars in the Taurus-Auriga cloud. We use STIS medium and low resolution spectra to derive the reddening, spectral type, and veiling for each component of close pairs with angular separations <= 1". This sample yields a frequency of mixed pairs, containing one classical and one weak emission T Tauri star, similar to that of wide pre-main sequence binaries. The components of most pairs are coeval, but the secondaries in four pairs are significantly younger than the primaries for the three sets of evolutionary tracks we considered.

2000, I.A.U. Symp. 200, Formation and Evolution of Binary Stars, H. Zinnecker and R. Mathieu eds.