NOAO >   Observing Info >   Approved Programs >   2013B-0140

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Proposal Information for 2013B-0140


PI: William van Altena, Yale University, william.vanaltena@yale.edu
Address: P.O. Box 20, New Haven, CT, 06520, USA

CoI: Elliott Horch, Southern Connecticut State University
CoI: Pierre Demarque, Yale University

Title: A Snapshot Improvement in the Metal-Poor Mass-Luminosity Relation

Abstract: This proposal seeks to obtain a single DSSI speckle observation of each of 22 binary systems which together can immediately impact the current understanding of the role of metallicity on the Mass-Luminosity Relation. Initial observations have been made at the WIYN 3.5-m Telescope in most cases, where most of the companions have been seen below the diffraction limit with DSSI. In these cases, a single (resolved) Gemini observation will provide definitive astrometry and photometry with which to calculate a high-precision orbit as well as individual magnitudes and colors, together with lower-precision data from WIYN or other sources. These systems are all spectroscopic binaries with known orbits and distances, so individual masses will immediately follow. With the full data set, it will be possible to make a major contribution to the main-sequence mass-luminosity relation for metal-poor stars, as well as to conduct very sensitive tests of the details of metal-poor stellar evolution models. For the lowest metallicity members in the sample, component colors and magnitudes would yield new points in the empirical Population II main sequence, which is important for the calibration of ages and distances to globular clusters.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2013B-0140

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