Related papers: Lithium in Blanco1: Implications for Stellar Mixin…
Lithium (Li) abundance is an age indicator for G, K, and M stellar types, as its abundance decreases over time for these spectral types. However, despite the observational efforts made over the past few decades, the role of rotation,…
High resolution spectroscopy is used to determine the detailed chemical abundances of a group of eight F- and G-type stars in the young open cluster Blanco 1. An average [Fe/H] of +0.04 +/- 0.02 (internal error) +/- 0.04 (external error) is…
The Lithium Depletion Boundary (LDB) is a robust method for accurately determining the ages of young clusters, but most pre-main-sequence models used to derive LDB ages do not include the effects of magnetic activity on stellar properties.…
We present results from a spectroscopic study of the very low mass members of the Southern open cluster Blanco 1 using the Gemini-N telescope. We obtained intermediate resolution (R~4400) GMOS spectra for 15 cluster candidate members with…
Lithium abundances in open clusters provide an effective way of probing mixing processes in the interior of solar-type stars and convection is not the only mixing mechanism at work. To understand which mixing mechanisms are occurring in…
The behavior of lithium (Li) in Population I main sequence stars challenges standard stellar theory. Two phenomena stand out: the solar Li problem which extends to Li depletion in solar analogs and the Li dip observed in mid-F stars within…
We have carried out a high resolution spectroscopic survey of the 220-250 Myr old cluster NGC 6475: our main purpose is to investigate Li evolution during the early stages of the Main Sequence. We have determined Li abundances for 33 late F…
The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among the physically best motivated ideas, it has been…
We have determined Li abundances for 11 G-type stars in the 6-8 Gyr old open cluster NGC 188. These data significantly enlarge the number of cluster stars with Li measurements, allowing us to extend the investigation of Li depletion in open…
Lithium abundances, radial velocities and rotational velocities are reported for 20 candidate F, G and K stars of the sparse Coma Berenices open cluster. All the stars are proper-motion selected, and our radial velocities support the…
We present lithium abundances for ~50 X-ray selected candidate members of the 30-50 Myr old open clusters IC 2602 and IC 2391. These data enlarge and extend to cooler temperatures previous Li surveys of these clusters by Stauffer et al.…
The disagreement between theoretical predictions and observations for surface lithium abundance in stars is a long-standing problem, which indicates that the adopted physical treatment is still lacking in some points. However, thanks to the…
We aim to constrain the mixing processes in low-mass stars by investigating the behaviour of the Li surface abundance after the main sequence. We take advantage of the data from the sixth internal data release of Gaia-ESO, idr6, and from…
I review basic observational features in Population I stars which strongly implicate rotation as a mixing agent; these include dispersion at fixed temperature in coeval populations and main sequence lithium depletion for a range of masses…
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…
Lithium abundances are presented and discussed for 70 members of the 50 Myr old open cluster alpha Per. More than half of the abundances are from new high-resolution spectra. The Li abundance in the F-type stars is equal to its presumed…
Mixing mechanisms bring the Li from the base of the convective zone to deeper and warmer layers where it is destroyed. These mechanisms are investigated by comparing observations of Li abundances in stellar atmospheres to models of stellar…
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…
Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We…
We compare the properties of recent samples of the lithium abundances in halo stars to one another and to the predictions of theoretical models including rotational mixing, and we examine the data for trends with metal abundance. We find…