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Related papers: Lithium in the Intermediate-Age Open Cluster, NGC …

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We present an analysis of the lithium abundances in late spectral type binaries of different ages. They belong to several open clusters (Pleiades, Hyades and M67), as well as to Chromospherically Active Binary Systems (CABS). All these…

Astrophysics · Physics 2007-05-23 David Barrado y Navascues

IC 4665 is one of only a dozen young open clusters with a ``lithium depletion boundary" (LDB) age. Using an astrometrically and spectroscopically filtered sample of cluster members, we show that both the positions of its low mass stars in…

Solar and Stellar Astrophysics · Physics 2023-09-15 R. D. Jeffries , R. J. Jackson , A. S. Binks

Lithium's susceptibility to burning in stellar interiors makes it an invaluable tracer for delineating the evolutionary pathways of stars, offering insights into the processes governing their development. Observationally, the complex Li…

We present deep CCD photometry of the very rich, intermediate aged (similar to the Hyades) open star cluster NGC 2099 (M37). The V, B-V color-magnitude diagram (CMD) for the cluster shows an extremely well populated and very tightly…

High resolution spectra (R > 40 000) for 9 main sequence turn-off stars and 9 subgiants in the globular cluster NGC 6752 were acquired with UVES on the VLT-Kueyen (UT2). These data have been used to determine the abundances of some heavy…

{The aim of this work is to investigate the relations between the abundances of different elements in the globular cluster M4, selected for its uniform deficiency of iron, to explore the best models explaining the pattern of these observed…

We conducted a homogeneous chemical analysis of pre-main sequence stars with effective temperatures ranging from $\sim$ 3000 K to $\sim$ 5500 K in eight nearby star-forming regions (SFRs): Chamaeleon I, $\eta$ Chamaeleonis, Lupus, Orion…

In this work we present the results of our analysis of 16,300 medium-resolution LAMOST spectra of late-type stars in the Kepler field with the aim of determining the stellar parameters, activity level, lithium atmospheric content, and…

Solar and Stellar Astrophysics · Physics 2022-08-17 A. Frasca , J. Molenda-Zakowicz , J. Alonso-Santiago , G. Catanzaro , P. De Cat , J. N. Fu , W. Zong , J. X. Wang , T. Cang , J. T. Wang

We present the high resolution (R $\approx$ 60000), high signal-to-noise (S/N $\simeq$ 120) spectroscopic analysis of 12 red giant members of the Galactic open cluster NGC 6940. We applied Yonsei-Yale isochrones to the color-magnitude…

Solar and Stellar Astrophysics · Physics 2019-03-12 G. Böcek Topcu , M. Afşar , C. Sneden

Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the 7Li line at 6707 {\AA} in high-resolution spectra obtained during gravitational microlensing events, when…

Astrophysics of Galaxies · Physics 2020-02-26 T. Bensby , S. Feltzing , J. C. Yee , J. A. Johnson , A. Gould , M. Asplund , J. Meléndez , S. Lucatello

The cosmological Li problem is the observed discrepancy between Li abundance, A(Li), measured in Galactic dwarf, old and metal-poor stars (traditionally assumed to be equal to the initial value A(Li)_0), and that predicted by standard Big…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. Mucciarelli , M. Salaris , P. Bonifacio , L. Monaco , S. Villanova

Elemental correlations and anti-correlations are known to be present in globular clusters (GCs) owing to pollution by CNO cycled gas. Because of its fragility Li is destroyed at the temperature at which the CNO cycling occurs, and this…

Astrophysics of Galaxies · Physics 2015-05-20 Z. -X. Shen , P. Bonifacio , L. Pasquini , S. Zaggia

We exploit the unique characteristics of a sample of open clusters (OCs) and field stars for which high-precision 7Li abundances and stellar parameters are homogeneously derived by the Gaia-ESO Survey (GES). We derive possibly undepleted…

We present the first comparisons of a newly developed Galactic Structure and Kinematic Model to magnitude and color counts, as well as relative proper motions, in the fields of the open clusters NGC 188 [(l, b)= (122.8 deg, +22.4 deg)] and…

Astrophysics · Physics 2009-10-28 R. A. Mendez , W. F van Altena

We present Gemini optical spectroscopy of 23 young star clusters in NGC3256. We find that the cluster ages range are from few Myr to ~150 Myr. All these clusters are relatively massive (2--40)x 10^{5} \msun$ and appear to be of roughly 1.5…

Astrophysics · Physics 2009-06-23 Gelys Trancho , Nate Bastian , Bryan W. Miller , François Schweizer

Open clusters have long been used to illuminate both stellar evolution and Galactic evolution. The oldest clusters, though rather rare, can reveal the chemical and nucleosynthetic processes early in the history of the Galaxy. We have…

Astrophysics of Galaxies · Physics 2015-05-13 Ann Merchant Boesgaard , Elizabeth E. C. Jensen , Constantine P. Deliyannis

We present an analysis of high quality spectra of members of the young cluster M35. By using a multi-fiber spectrograph, we are able to collect high signal-to-noise, high resolution spectra of a sample of photometric candidate members.…

Astrophysics · Physics 2009-10-31 D. Barrado y Navascues , Constantine P. Deliyannis , John R. Stauffer

The discovery of the Spite plateau in the abundances of 7Li for metal-poor stars led to the determination of an observationally deduced primordial lithium abundance. However, after the success of the Wilkinson Microwave Anisotropy Probe…

Astrophysics · Physics 2009-11-13 A. Hosford , S. G. Ryan , A. E. Garcia Perez , J. E. Norris , K. A. Olive

Standard stellar evolution model predicts a severe depletion of lithium (Li) abundance during the first dredge-up process (FDU). Yet a small fraction of giant stars are still found to preserve a considerable amount of Li in their…

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