NOAO >   Observing Info >   Approved Programs >   2010B-0486

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Proposal Information for 2010B-0486


PI: Ryan M. Maderak, Indiana University, maderak@astro.indiana.edu
Address: Astronomy Department, Swain West 319, 727 E 3rd St., Bloomington, IN 47405-7105, USA

CoI: Constantine P. Deliyannis, Indiana University
CoI: Andrew Szentgyorgyi, CfA

Title: Probing Chemical Evolution and Cool Dwarf Atmospheres with Oxygen in M67

Abstract: The chemical evolution of oxygen is of great importance for our understanding of Galactic chemical evolution. Furthermore, oxygen may at the same time provide a novel probe of cool dwarf atmospheres. Open clusters have been found to exhibit a strong [O/H] vs. age relationship, suggesting that oxygen is a superior chronometer for Galactic chemical evolution, but surprisingly have not yet been robustly shown to exhibit the [O/Fe] vs. [Fe/H] observed in field stars. In addition, the discovery of an overabundance trend for the near infrared oxygen triplet in cool open cluster dwarfs is an unresolved mystery. Open clusters are unique in providing both knowable ages and accurate abundances, a combination not possible for field stars. Our ongoing WIYN/Hydra and MMT/Hectochelle study of open cluster dwarf oxygen abundances seeks to define the [O/H] vs. age relationship, resolve the apparent [O/Fe] vs. [Fe/H] discrepancy between open clusters and field stars, and explore the nature of the cool star overabundance trend. The [Fe/H] and age ranges of our sample will allow us to address all of these questions simultaneously. However, anchoring our sample and analysis to solar age and metallicity is essential. We propose to observe M67 with MMT/Hectochelle, uniquely providing both of these points in parameter space, and providing the sampling density in T_eff neccesary to deliver a precise determination of its cool star overabundance trend.


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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