Poster Abstracts

Name/Affiliation:  Francis C. Fekel, Michael H. Williamson, Matthew W. Muterspaugh, Jocelyn Tomkin (Tennessee State University)

Title:  A Progress Report on New Spectroscopic Orbits of Potential Interferometric Binaries

We discuss the status of a program to obtain radial velocities from high-resolution, red-wavelength spectra to improve the orbits of bright known spectroscopic binaries that are potential targets of ground-based interferometers. Most of the 30 orbits still to be published are solar-type stars or late-type giants. Of the 55 systems that have been extensively observed in this project, four or 7% have been found spectroscopically to have a long-period companion, making the systems at least triple. Of the remaining 30 systems, we have detected the secondary of a dozen former single-lined binaries. The combination of spectroscopy and astrometry from interferometric observations will result in three-dimensional orbits and so will produce many additional systems with masses to better than 1% and well determined distances. Orbital inclinations for some of our stars can also be obtained with astrometry from the upcoming GAIA mission.