LITHIUM ABUNDANCES OF THE SUPER-METAL-RICH OPEN CLUSTER NGC 6253

Journal Article · Thu Nov 01 00:00:00 EDT 2012 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/144/5/137· OSTI ID:22089820

Cummings, Jeffrey D. ^[1]; Deliyannis, Constantine P.; Maderak, Ryan M. ^[2]; Anthony-Twarog, Barbara; Twarog, Bruce ^[3]

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1. Departamento de Astronomia, Universidad de Concepcion 160-C Casilla, Concepcion (Chile)
2. Department of Astronomy, Indiana University Bloomington, IN 47405-7105 (United States)
3. Department of Physics and Astronomy, University of Kansas Lawrence, KS 66045-7582 (United States)

High-resolution CTIO 4 m/HYDRA spectroscopy of the super-metal-rich open cluster NGC 6253 ([Fe/H] = +0.43 {+-} 0.01) has been used to study the stellar lithium (Li) abundances near the cluster's turnoff. NGC 6253 greatly expands the range of [Fe/H] for clusters that have a Li abundance analysis. This is important for studying the complicated effects of, and potential correlations with, stellar Fe abundance on surface Li abundance. Comparisons to the younger and less-metal-rich Hyades and to the similarly aged but solar-metallicity M67 show that NGC 6253's Li abundances are qualitatively consistent with the prediction, from Standard Stellar Evolution Theory, that higher-metallicity stars have a greater Li depletion. Comparison with M67 provides evidence that the more-metal-rich NGC 6253 had a higher initial Li, which is consistent with expectations from models of Galactic Li production. NGC 6253 is also compared to the intermediate-aged NGC 3680, NGC 752, and IC 4651 open clusters. Comparison of the Li-gap positions in all six clusters shows that (1) the gap's position in T{sub eff} is independent of metallicity, but (2) higher-metallicity clusters have their gaps in higher-mass stars. In addition, the Li gap's position is shown not to evolve with age, which provides an important constraint for the non-standard depletion mechanisms that may create the Li gap.

• OSTI ID: 22089820
• Journal Information: Astronomical Journal (New York, N.Y. Online), Vol. 144, Issue 5; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTRONOMY
ASTROPHYSICS
COMPARATIVE EVALUATIONS
CORRELATIONS
ELEMENT ABUNDANCE
HYDROGEN
IRON
LITHIUM
MASS
RESOLUTION
STAR CLUSTERS
STAR EVOLUTION
STARS