English
Related papers

Related papers: Membership and lithium in the old, metal-poor open…

200 papers

During Big Bang nucleosynthesis (BBN) in the first 15 minutes of the Universe some $^7$Li was created along with isotopes of H and He. The determination of that primordial value of Li can help constrain the conditions at that time. The…

Solar and Stellar Astrophysics · Physics 2024-06-26 Ann Merchant Boesgaard , Constantine P. Deliyannis

We obtained high-resolution UVES/FLAMES observations of a sample of nine old open clusters spanning a wide range of ages and Galactocentric radii. The goal of the project is to investigate the radial metallicity gradient in the disk, as…

Astrophysics · Physics 2010-11-23 P. Sestito , A. Bragaglia , S. Randich , E. Carretta , L. Prisinzano , M. Tosi

We find that hot jupiter host stars within the T$_\mathrm{eff}$ range 5900-6300K show lower Li abundances, by 0.14 dex, than stars without detected planets. This offset has a significance at the level 7$\sigma$, pointing to a stronger…

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…

The dispersion in lithium abundance at fixed effective temperature in young cool stars like the Pleiades has proved a difficult challenge for stellar evolution theory. We propose that Li abundances relative to a mean temperature trend,…

Astrophysics · Physics 2009-10-31 Jeremy King , Anita Krishnamurthi , Marc H. Pinsonneault

Most Globular Clusters are believed to host a single stellar populations. They can thus be considered a good place to study the Spite plateau and probe for possible evolutionary modifications of the Li content. We want to determine the Li…

Astrophysics of Galaxies · Physics 2015-05-14 J. I. Gonzalez Hernandez , P. Bonifacio , E. Caffau , M. Steffen , H. -G. Ludwig , N. T. Behara , L. Sbordone , R. Cayrel , S. Zaggia

Context: Lithium is a fragile element, which is easily destroyed in the stellar interior. The existence of lithium-rich giants still represents a challenge for stellar evolution models. Aims: We have collected a large database of…

Solar and Stellar Astrophysics · Physics 2015-05-27 L. Monaco , S. Villanova , C. Moni Bidin , G. Carraro , D. Geisler , P. Bonifacio , O. A. Gonzalez , M. Zoccali , L. Jilkova

We present Li and Fe abundances for 87 stars in the GC M4,obtained with GIRAFFE high-resolution spectra. The targets range from the TO up to the RGB Bump. The Li abundance in the TO stars is uniform, with an average value A(Li)=2.30+-0.02…

Solar and Stellar Astrophysics · Physics 2015-05-20 A. Mucciarelli , M. Salaris , L. Lovisi , F. R. Ferraro , L. Lanzoni , S. Lucatello , R. G. Gratton

Open cluster members are coeval and share the same initial bulk chemical compositions. Consequently, differences in surface abundances between members of a cluster that are at different evolutionary stages can be used to study the effects…

We report on a new, wide field ($20^{\prime} \times 20^{\prime}$), multicolor ($UBVI$), photometric campaign in the area of the nearby old open cluster NGC 2112. At the same time, we provide medium-resolution spectroscopy of 35 (and…

We present high-resolution spectroscopic observations of the \ion{Li}{1} resonance line in a sample of 62 stars that belong to 31 common-proper motion pairs with twin F or G-type components. Photospheric abundances of lithium were derived…

Astrophysics · Physics 2009-11-07 Eduardo L. Martin , Gibor Basri , Yakiv Pavlenko , Yuri Lyubchik

We present high resolution observations (FWHM=15 km/sec) of the Li region in 5 stars belonging to the old (14 Gyrs), metal rich ([Fe/H]=-0.7) globular cluster 47Tuc. At the ESO NTT telescope we obtained EMMI spectra for three V about 17.4…

Astrophysics · Physics 2011-05-23 Luca Pasquini , Paolo Molaro

The stellar evolution of lithium-rich (Li-rich) giant stars at very low metallicities remains largely unexplored to date. Using two recent large LAMOST catalogues of field, low-mass giant stars (both Li-rich and Li-poor) with metallicities…

Astrophysics of Galaxies · Physics 2025-12-30 Ramiro de la Reza , Felix Llorente de Andrés , Emilio J. Alfaro , Carolina Chavero

We employ a new Infrared Flux Method (IRFM) temperature scale (Ramirez & Melendez 2005, ApJ 626, 446; ApJ 626, 465) in order to determine Li, O, and Fe NLTE abundances in a sample of relatively unevolved (dwarfs, turn-off, subgiants)…

Astrophysics · Physics 2009-11-11 Jorge Melendez , Nataliya G. Shchukina , Ivan Ramirez , Irina Vasiljeva

We present a study of beryllium (Be) abundances in a large sample of field solar-type dwarfs and sub-giants spanning a large range of effective temperatures. The analysis shows that Be is severely depleted for F stars, as expected by the…

Astrophysics · Physics 2009-11-10 N. C. Santos , G. Israelian , S. Randich , R. J. Garcia Lopez , R. Rebolo

We report the discovery of eight lithium-rich field giants found in a high resolution spectroscopic sample of over 700 metal-poor stars ([Fe/H]<-0.5) selected from the RAVE survey. The majority of the Li-rich giants in our sample are very…

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

Observational constraints on the primordial lithium abundance are important for the evaluation of the baryonic density of the universe. Its precise determination however suffers from uncertainties due to the possible depletion of this…

Astrophysics · Physics 2009-10-30 Sylvie Vauclair , Corinne Charbonnel

We provide the whole set of Lick indices from CN1 to TiO2 of Simple Stellar Population models with, for the first time, variable element abundance ratios, [alpha/Fe]=0.0, 0.3, 0.5, [alpha/Ca]=-0.1, 0.0, 0.2, 0.5, and [alpha/N]=-0.5, 0.0.…

Astrophysics · Physics 2009-11-07 Daniel Thomas , Claudia Maraston , Ralf Bender

We report discovery of significant depletion of Li on the surfaces of F dwarf stars in the 150-Myr-old open cluster M35, analagous to a feature in the 700-Myr-old Hyades cluster that has been referred to as the ``Li gap.'' We have caught…

Astrophysics · Physics 2009-11-10 Aaron Steinhauer , Constantine P. Deliyannis