711 research outputs found
In Christ ... a future with hope
Historical series, 18. Sermon preached at the opening service of the Saskatchewan Synod Convention, Swift Current, Saskatchewan, 4 Jl 2002. Jer 29:11-14; Rom 8:18-27; Jn 17:1-6, 17-26
We would see Jesus
Historical series, 10. Jn 12:20-33. Preached during Lent, 1997, Hodgeville Lutheran parish
Nitrogen abundances in giant stars of the globular cluster NGC 6752
We present N abundances for 21 bright giants in the globular cluster NGC 6752
based on high-resolution UVES spectra of the 3360A NH lines. We confirm that
the Stromgren c1 index traces the N abundance and find that the star-to-star N
abundance variation is 1.95 dex, at the sample's luminosity. We find
statistically significant correlations, but small amplitude variations, between
the abundances of N and alpha-, Fe-peak, and s-process elements. Analyses using
model atmospheres with appropriate N, O, Na, and Al abundances would
strengthen, rather than mute, these correlations. If the small variations of
heavy elements are real, then the synthesis of the N anomalies must take place
in stars which also synthesize alpha-, Fe-peak, and s-process elements. These
correlations offer support for contributions from both AGB and massive stars to
the globular cluster abundance anomalies.Comment: Accepted for publication in Ap
Observational signatures of lithium depletion in the metal-poor globular cluster NGC6397
The "stellar" solution to the cosmological lithium problem proposes that
surface depletion of lithium in low-mass, metal-poor stars can reconcile the
lower abundances found for Galactic halo stars with the primordial prediction.
Globular clusters are ideal environments for studies of the surface evolution
of lithium, with large number statistics possible to obtain for main sequence
stars as well as giants. We discuss the Li abundances measured for >450 stars
in the globular cluster NGC6397, focusing on the evidence for lithium depletion
and especially highlighting how the inferred abundances and interpretations are
affected by early cluster self-enrichment and systematic uncertainties in the
effective temperature determination.Comment: 6 pages, 2 figures, conference proceedings for IAU symposium 26
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