Proton Capture Chains in Globular Cluster Stars. III. Abundances of Giants in the Second-Parameter Globular Cluster NGC 7006

1998 ◽  
Vol 115 (4) ◽  
pp. 1500-1515 ◽  
Author(s):  
Robert P. Kraft ◽  
Christopher Sneden ◽  
Graeme H. Smith ◽  
Matthew D. Shetrone ◽  
Jon Fulbright
Keyword(s):  
Globular Cluster ◽  
Proton Capture

Proton‐Capture Nucleosynthesis in Globular Cluster Red Giant Stars

1998 ◽  
Vol 492 (2) ◽  
pp. 575-595 ◽  
Author(s):  
Robert M. Cavallo ◽  
Allen V. Sweigart ◽  
Roger A. Bell
Keyword(s):  
Globular Cluster ◽  
Proton Capture ◽  
Giant Stars ◽  
Red Giant Stars ◽  
Red Giant

Proton Capture Chains in Globular Cluster Stars.II.Oxygen, Sodium, Magnesium, and Aluminum Abundances in M13 Giants Brighter Than the Horizontal Branch

1997 ◽  
Vol 113 ◽  
pp. 279 ◽  
Author(s):  
Robert P. Kraft ◽  
Christopher Sneden ◽  
Graeme H. Smith ◽  
Matthew D. Shetrone ◽  
G. E. Langer ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Horizontal Branch ◽  
Proton Capture ◽  
Sodium Magnesium

scholarly journals Aluminium abundances in five discrete stellar populations of the globular cluster NGC 2808

2018 ◽  
Vol 615 ◽  
pp. A17 ◽  
Author(s):  
Eugenio Carretta ◽  
Angela Bragaglia ◽  
Sara Lucatello ◽  
Raffaele G. Gratton ◽  
Valentina D’Orazi ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Cluster Formation ◽  
Light Elements ◽  
Atmospheric Parameters ◽  
Proton Capture ◽  
Full Dataset ◽  
Self Consistent ◽  
Red Giant ◽  
Set Up ◽  
First Time

We observed a sample of 90 red giant branch (RGB) stars in NGC 2808 using FLAMES/GIRAFFE and the high resolution grating with the set-up HR21. These stars have previous accurate atmospheric parameters and abundances of light elements. We derived aluminium abundances for them from the strong doublet Al i 8772–8773 Å as in previous works of our group. In addition, we were able to estimate the relative CN abundances for 89 of the stars from the strength of a large number of CN features. When adding self-consistent abundances from previous UVES spectra analysed by our team, we gathered [Al/Fe] ratios for a total of 108 RGB stars in NGC 2808. The full dataset of proton-capture elements is used to explore in detail the five spectroscopically detected discrete components in this globular cluster. We found that various classes of polluters are required to reproduce (anti)-correlations among all proton-capture elements in the populations P2, I1, and I2 with intermediate composition. This is in agreement with the detection of lithium in lower RGB second generation stars, requiring at least two kind of polluters. For chemically homogeneous populations, the best subdivision of our sample is into six components as derived from statistical cluster analysis. By comparing different diagrams [element/Fe] versus [element/Fe], we show for the first time that a simple dilution model is not able to reproduce all the subpopulations in this cluster. Polluters of different masses are required. NGC 2808 is confirmed to be a tough challenge to any scenario for globular cluster formation.

scholarly journals LITHIUM AND PROTON-CAPTURE ELEMENTS IN GLOBULAR CLUSTER DWARFS: THE CASE OF 47 TUC

2010 ◽  
Vol 713 (1) ◽  
pp. L1-L5 ◽  
Author(s):  
Valentina D'Orazi ◽  
Sara Lucatello ◽  
Raffaele Gratton ◽  
Angela Bragaglia ◽  
Eugenio Carretta ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Proton Capture

scholarly journals Proton capture elements in the globular cluster NGC 2808

2003 ◽  
Vol 410 (1) ◽  
pp. 143-154 ◽  
Author(s):  
E. Carretta ◽  
A. Bragaglia ◽  
C. Cacciari ◽  
E. Rossetti
Keyword(s):  
Globular Cluster ◽  
Proton Capture

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

A Distance-Independent Age for the Globular Cluster M92

2000 ◽  
Vol 120 (4) ◽  
pp. 1884-1891 ◽  
Author(s):  
F. Grundahl, ◽  
D. A. VandenBerg, ◽  
R. A. Bell, ◽  
M. I. Andersen, ◽  
P. B. Stetson
Keyword(s):  
Globular Cluster

Elemental Abundances in Five Stars in M54, A Globular Cluster Associated with the Sagittarius Galaxy

1999 ◽  
Vol 118 (3) ◽  
pp. 1245-1251 ◽  
Author(s):  
Jeffery A. Brown ◽  
George Wallerstein ◽  
Guillermo Gonzalez
Keyword(s):  
Globular Cluster ◽  
Elemental Abundances
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