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Related papers: Baryonic Density from Primordial Li

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As an investigation of the origin of ``$\alpha$-poor'' halo stars, we analyze kinematic and abundance data for 73 intermediate metallicity stars ($-1 >$ [Fe/H] $\geq -2$) selected from Paper I of this series. We find evidence for a…

Astrophysics · Physics 2009-12-08 Jon P. Fulbright

The primordial abundance of deuterium (D/H) yields a measure of the density of baryons in the universe and is an important complement to determinations from cosmic microwave background (CMB) experiments. Indeed, the current small sample of…

Astrophysics · Physics 2009-11-13 Sara L. Ellison , Jason X. Prochaska , Sebastian Lopez

We report on a attempt to detect beryllium in two dwarf stars of the Galactic halo with metallicities below one thousandth solar. The data were obtained during the Commissioning of the Ultraviolet and Visible Echelle Spectrograph (UVES)…

Astrophysics · Physics 2007-05-23 Francesca Primas , Paolo Molaro , Piercarlo Bonifacio , Vanessa Hill

Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the…

Lithium and zirconium abundances (the latter taken as representative for s-process enrichment) are determined for a large sample of massive Galactic O-rich AGB stars, for which high resolution optical spectroscopy has been obtained…

Astrophysics · Physics 2009-11-11 D. A. Garcia-Hernandez , P. Garcia-Lario , B. Plez , A. Manchado , F. D'Antona , J. Lub , H. Habing

We present new results from our spectral analyses of very hot central stars achieved since the last IAU Symposium on planetary nebulae held in Canberra 2001. The analyses are mainly based on UV and far-UV spectroscopy performed with the…

Astrophysics · Physics 2009-11-13 K. Werner , A. I. D. Hoffmann , D. Jahn , T. Rauch , E. Reiff , I. Traulsen , J. W. Kruk , S. Dreizler

We report the discovery of 34 stars in the Hamburg/ESO Survey for metal-poor stars and the Sloan Digital Sky Survey that have [Fe/H] < -3.0. Their median and minimum abundances are [Fe/H] = -3.1 and -4.1, respectively, while 10 stars have…

We present a non-local thermodynamic equilibrium abundance analysis of the resonance doublet Li I at 6707.8 A for 55 Galactic F and G supergiants and bright giants. The derived lithium abundances log \epsilon(Li) may be considered in three…

We present preliminary results of a detailed chemical abundance analysis for a sample of solar-type stars known to exhibit excess infrared emission associated with dusty debris disks. Our sample of 28 stars was selected based on results…

Solar and Stellar Astrophysics · Physics 2015-06-17 Adam M. Ritchey , Guillermo Gonzalez , Myra Stone , George Wallerstein

We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B < 14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was only…

[ABRIDGED] We determine Li abundances for a well-studied sample of 714 F and G dwarf, turn-off, and subgiant stars in the solar neighbourhood. The analysis is based on line synthesis of the Li line at 6707 {\AA} in high-resolution and high…

Astrophysics of Galaxies · Physics 2018-08-01 Thomas Bensby , Karin Lind

Abundances of 18 elements are determined for the common proper-motion pair, HD134439 and HD134440, which shows high [Mn/Fe] and low [\alpha/Fe] ratios as compared to normal halo stars. Moreover, puzzling abundances are indicated from…

Astrophysics · Physics 2009-11-11 Y. Q. Chen , G. Zhao

We report on the determination of the lithium abundance [A(Li)] of 52 solar-like stars. For 41 objects the A(Li) here presented corresponds to the first measurement. We have measured the equivalent widths of the 6708\AA\ lithium feature in…

Solar and Stellar Astrophysics · Physics 2015-07-07 R. López-Valdivia , J. B. Hernández-Águila , E. Bertone , M. Chávez , F. Cruz-Saenz de Miera , E. M. Amazo-Gómez

Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been…

Astrophysics · Physics 2008-02-03 Scott Burles , David Tytler

We examine the evolution of Li in the Galactic disk,basing our model on the compilation of Li v.Fe observations in stars of iron abundance ranging between halo values,which give a baseline for the disk Li abundance,and 0.2 dex above…

Astrophysics · Physics 2007-05-23 E , Casuso , J. E. Beckman

The low second acoustic peak in the recent Boomerang data may indicate a cosmological baryon density which is larger than allowed by standard big bang nucleosynthesis. We show that the decay of the tau-neutrino: nu_tau -> nu_e + phi, where…

Astrophysics · Physics 2009-10-31 S. H. Hansen , F. L. Villante

We derive lithium abundances in 53 T Tauri stars (TTS), concentrating on weak-line TTS. Our study gives the following results: 1)At luminosities $\ge 0.9 L\sun$ the Li abundances are remarkably uniform, with a mean value, log~N(Li)=3.1,…

Astrophysics · Physics 2019-08-17 E. L. Martin , R. Rebolo , A. Magazzu , Ya. V. Pavlenko

First results from a study into the abundance trends of oxygen in the Galactic thin and thick disks are presented. Oxygen abundances for 63 nearby F and G dwarf stars, based on very high resolution spectra ($R\sim215 000$) and high…

Astrophysics · Physics 2010-04-28 T. Bensby , S. Feltzing , I. Lundström

In an attempt to carry out a systematic study on the behavior of the photospheric abundances of Li, C, and O (along with Fe) for Hyades main-sequence stars in the T_eff range of ~5000-7000K, we conducted an extensive spectrum-synthesis…

Solar and Stellar Astrophysics · Physics 2015-06-12 Yoichi Takeda , Satoshi Honda , Takashi Ohnishi , Michiko Ohkubo , Ryuko Hirata , Kozo Sadakane

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
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