NOAO >   Observing Info >   Approved Programs >   2004A-0427

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Proposal Information for 2004A-0427


PI: Terry D. Oswalt, Florida Institute of Technology, oswalt@luyten.astro.fit.edu
Address: Physics Department, 150 W. University Blvd., Melbourne, FL 32901, USA

CoI: Sydney Barnes, Florida Institute of Technology
CoI: Merissa Rudkin, Florida Institute of Technology
CoI: Nigel Hambly, Edinburgh University
CoI: Nicole Silvestri, University of Washington
CoI: Suzanne Hawley, University of Washington

Title: White Dwarf Cooling Times and the Chromospheric Activity - Age Relations for Lower Main Sequence Stars

Abstract: We propose to investigate the chromospheric activity (CA) vs. age relation among lower main sequence (MS) stars using noninteracting binaries that contain a white dwarf (WD) star with a distant cool MS companion. The cooling ages of the WD components, and therefore the ages of their coeval MS companions, span the entire history of the local Galactic disk (~10 Gyr). This age range overlaps with and extends by more than a factor of two the CA-age calibration possible by other approaches. The project will help resolve strong systematic differences between MS age estimates derived from open cluster (OC) membership, rotation rates, Li abundance and UV/X-ray fluxes. It will also explore the transition region in early dM stars where the canonical self- sustaining dynamo mechanism gives way to other processes that do or do not excite CA. In addition, the sample selected will facilitate one of the first investigations of CA vs. age in low metallicity (i.e. halo) stars.


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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