NOAO > Observing Info > Approved Programs > 2000B-0192
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NOAO > Observing Info > Approved Programs > 2000B-0192 |
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PI: Brian D. Mason, U.S. Naval Observatory, bdm@draco.usno.navy.mil
Address: 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420, USA
CoI: William I. Hartkopf, U.S. Naval Observatory
CoI: Todd J. Henry, Johns Hopkins University
CoI: Theodore J. Rafferty, U.S. Naval Observatory
CoI: David R. Soderblom, Space Telescope Science Institute
CoI: Sean E. Urban, U.S. Naval Observatory
CoI: Arsen R. Hajian, U.S. Naval Observatory
Title: A Multiplicity Survey of Nearby G Dwarf Stars
Abstract: We propose to complete a survey of all (N=3589) solar-type (0.5 < B-V < 1.0), nearby (d < 50 pc) stars for multiplicity. While visual speckle interferometry provides data for the closest separations (0\farcs03 < \rho < 2'' on a 4-m telescope), inclusion of data from the USNO CCD Astrograph project will allow us to extend this to >60'' (corresponding to physical separations of 1.5 to 3000 AU at 50 pc for both techniques). While this provides important data about star formation processes for those stars most like the Sun, the information is also relevant to planetary searches due to the hierarchical nature of multiple systems. Further, the survey of stars fitting the above criteria can be divided into two subsets, a younger population with active chromospheric emission and an older inactive population. Earlier results of a subset of this list (Mason et al.\ 1998) demonstrated a relationship between multiplicity and age which warrants further investigation - roughly 18% of stars of age ~1 Gyr had companions between 2 and 127 AU, while only 9% of stars of age ~4 Gyr had such companions. In this survey, we will not only determine the multiplicity of solar type stars in a large sample, we will investigate whether the multiplicity fraction of solar-type stars evolves after a few hundred million years, which might have serious implications for the survivability of planetary systems.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2000B-0192 |
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