Poster Abstracts

Name/Affiliation:  Gail Schaefer (Georgia State University)

Title:  Orbital Motion in Pre-Main Sequence Binaries

We present results from our ongoing program to map the visual orbits of pre-main sequence binaries in the Taurus star forming region using adaptive optics imaging at the Keck Observatory. We combine our results with measurements reported in the literature to analyze the orbital motion for each binary. We present preliminary orbits for DF Tau, T Tau S, and ZZ Tau. Seven additional binaries show curvature in their relative motion; currently we can place lower limits on their orbital periods. Five other binaries show motion that is indistinguishable from linear motion. We suspect that these systems are bound and might show curvature with additional measurements in the future. These observations lay critical groundwork toward the goal of measuring precise masses for low-mass pre-main sequence stars.