PI: Wei-Chun Jao, Georgia State University, email@example.com
Address: Physics Department, P.O. Box 4106, Atlanta 30302-4106, USA
CoI: Todd Henry, Georgia State University
CoI: Russel White, Georgia State University
CoI: Adric Riedel, Georgia State University
Title: The Dancing Partners of Seven Dwarfs
Abstract: We propose to use Gemini South's Phoenix echelle spectrograph to determine masses of red and brown dwarfs, and perhaps the nearest neutron star, in conjunction with astrometrically-determined orbits from our continuing program at CTIO. Radial velocities accurate to ~300 m/sec will be used to constrain the derived three-dimensional orbits of seven binaries discovered via astrometric monitoring during the past 10 years. These seven targets were carefully selected from 58 definitive or likely perturbations from our program (which in total has targeted more than 500 stars). The five main-sequence red dwarf primaries harbor unseen companions ranging from a possible neutron star to brown dwarfs. The two red subdwarf primaries are rare in that they have companions at separations appropriate for mass determinations, few of which have been accomplished for low mass subdwarfs. Ultimately, this study has the potential to (a) reveal what may be the nearest neutron star, (b) provide four red subdwarf masses, and (c) measure accurate masses for several very nearby brown dwarfs. This proposal is to obtain two velocities for each target during 2010A, and will likely be followed by additional proposals in future years, pending successful observations.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360