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Related papers: Lithium abundance in a turnoff halo star on an ext…

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The vast majority of low-metal halo dwarfs show a similar amount of Li; this has been attributed to the Li that was produced in the Big Bang. However, there are nine known halo stars with T $>$ 5900 K and [Fe/H] $<$ $-$1.0 that are…

Astrophysics · Physics 2009-11-13 Ann Merchant Boesgaard , Megan C. Novicki

Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced…

We report results from lithium abundance determinations using high resolution spectral analysis of the 107 metal-rich stars from the Calan-Hertfordshire Extrasolar Planet Search programme. We set out to understand the lithium distribution…

Solar and Stellar Astrophysics · Physics 2018-03-21 Ya. V. Pavlenko , J. S. Jenkins , O. M. Ivanyuk , H. R. A. Jones , B. M. Kaminsky , Yu. P. Lyubchik , L. A. Yakovina

We report on the discovery of a super-Li rich turn-off star in the old (12 Gyr), metal poor ([Fe/H]=-2.1 dex) globular cluster (GC) NGC 6397, based on high-resolution MIKE/Magellan spectra. This star shows an unusually high lithium…

Astrophysics of Galaxies · Physics 2015-05-30 Andreas Koch , Karin Lind , R. Michael Rich

This paper presents the chemical abundance analysis of 217 stars in the metal-poor globular cluster NGC 6752, distributed from the turn-off to the lower red giant branch. Aluminium and Lithium abundances were derived through spectral…

Solar and Stellar Astrophysics · Physics 2022-02-09 J. Schiappacasse-Ulloa , S. Lucatello , M. J. Rain , A. Pietrinferni

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…

Solar and Stellar Astrophysics · Physics 2015-05-18 K. Lind , F. Primas , C. Charbonnel , F. Grundahl , M. Asplund

There are nine metal-deficient stars that have Li abundances well below the Li plateau that is defined by over 100 unevolved stars with temperatures above 5800 K and values of [Fe/H] $<$ $-$1.0. Abundances of Be have been determined for…

Astrophysics · Physics 2009-11-13 Ann Merchant Boesgaard

Lithium depletion and enrichment in the cosmos is not yet well understood. To help tighten constraints on stellar and Galactic evolution models, we present the largest high-resolution analysis of Li abundances A(Li) to date, with results…

It has recently been suggested that all giant stars with mass below 2 $M_{\odot}$ suffer an episode of surface lithium enrichment between the tip of the red giant branch (RGB) and the red clump (RC). We test if the above result can be…

We present the discovery of 2MASS J05241392-0336543 (hereafter J0524-0336), a very metal-poor ([Fe/H]=-2.43 +- 0.16), highly r-process-enhanced ([Eu/Fe]= +1.34 +- 0.10) Milky Way halo field red giant star, with an ultra high Li abundance of…

We present chemical abundances of the very bright metal-poor star HD~1936 based on high-resolution and high SNR spectra from AUKR. We obtain the abundances of 29 atomic species with atomic numbers between 3 and 63. In this context, the…

Solar and Stellar Astrophysics · Physics 2024-02-16 Şeyma Çalışkan , Jannat Mushreq Kamil Alazzawi , Yahya Nasolo

Recent detection of the isotope $^7$Be (that decays into $^7$Li) in the outburst of classical novae confirms the suggestion made in the 70s that novae could make $^7$Li. We reconsidered the role of novae as producers of Li by means of a…

Solar and Stellar Astrophysics · Physics 2019-01-16 Gabriele Cescutti , Paolo Molaro

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

Spectroscopic analysis of the Galactic halo star SDSS J102915+172927 has shown it to have a very low heavy element abundance, Z < 7.4 10-7, with [Fe/H] = -4.89 plus/minus 0.10 and an upper limit on the C abundance of [C/H] < -4.5. The low…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. MacDonald , T. M. Lawlor , N. Anilmis , N. F. Rufo

Li abundances are derived for a sample of bulgelike stars with isochronal ages of 10-11 Gyr. These stars have orbits with pericentric distances, Rp, as small as 2-3 kpc and Zmax < 1 kpc. The sample comprises G and K dwarf stars in the…

Astrophysics · Physics 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon , Bruno Castilho

{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…

In 1982, Monique and Francois Spite discovered that the 7Li abundance in the atmosphere of old metal-poor dwarf stars in the galactic halo was independent of metallicity and temperature. Since then, 7Li abundance in the Universe has become…

High Energy Astrophysical Phenomena · Physics 2014-02-24 Rachid Ouyed

The abundances of alkali elements (Li, Na, and K) were determined from the Li I 6708, Na I 5682/5688, and K I 7699 lines by taking into account the non-LTE effect for 24 sharp-lined A-type stars v sin i < 50 km/s, 7000 K < Teff <10000 K,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Yoichi Takeda , Dong-Il Kang , Inwoo Han , Byeong-Cheol Lee , Kang-Min Kim , Satoshi Kawanomoto , Naoko Ohishi

This work presents a homogeneous determination of lithium abundances in a large sample of giant-planet hosting stars (N=117), and a control sample of disk stars without detected planets (N=145). The lithium abundances were derived using a…

Solar and Stellar Astrophysics · Physics 2010-11-04 L. Ghezzi , K. Cunha , V. V. Smith , R. de la Reza

We present NLTE Li abundances for 88 stars in the metallicity range -3.5 < [Fe/H] < -1.0. The effective temperatures are based on the infrared flux method with improved E(B-V) values obtained mostly from interstellar NaI D lines. The Li…

Solar and Stellar Astrophysics · Physics 2015-05-19 Jorge Melendez , Luca Casagrande , Ivan Ramirez , Martin Asplund , William Schuster