NOAO > Observing Info > Approved Programs > 2011B-0581
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NOAO > Observing Info > Approved Programs > 2011B-0581 |
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PI: Sebastien Lepine, American Museum of Natural History, lepine@amnh.org
Address: Astrophysics, Central Park West at 79th street, New York, NY 10024, USA
CoI: Saurav Dhital, Vanderbilt University
CoI: Andrew A. West, Boston University
Title: Calibration the absolute metallicity scale of M subdwarfs using wide, common proper motion binaries.
Abstract:
Metallicity is a fundamental parameter but is very hard to measure
in low-mass stars such as M dwarfs and M subdwarfs (sdM) due to the
complexity of their emerging spectra. Metallicity sensitive features
have recently been identified in the metal-poor M subdwarfs but their
calibration is currently based on just a few early-type sdM objects,
which are just bright enough for Fe abundance measurements with high-
resolution spectroscopy; all other known M subdwarfs are too faint for
similar measurement to be carried out. However, we have just identified
60 common proper motion pairs, where the secondary is a faint, M
subdwarf but the primary is a much brighter star of subtype F/G/K.
Metallicities can be estimated for these primaries using existing
stellar parameter pipelines. We propose to use these wide halo binaries
to calibrate the metallicity scale of the M subdwarfs by measuring the
metallicity of the more massive F/G/K primary.
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 > 2011B-0581 |
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