Evolution of lithium beyond the solar age: a Li survey of the old open cluster NGC 188

Abstract

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 clusters to ages well beyond the age of the Sun. We have also inferred the cluster metallicity which turns out to be solar. We find that solar-type stars in NGC 188 are only slightly more Li depleted than the much younger Hyades and no more Li depleted than stars of similar temperature in the 2-4 Gyr younger cluster M 67. At variance with M 67, NGC 188 members show virtually no scatter in their Li abundances. Surprisingly, no solar- type star in NGC 188 appears as Li depleted as the Sun or as the most Li depleted stars in M 67. We discuss the implications of these results for mechanisms of internal mixing and Li depletion in main sequence stars.

arXiv commentto appear in A&A

References in corpus (5)

• Stellar Models with Microscopic Diffusion and Rotational Mixing I: Application to the Sun
• The lithium content of the globular cluster NGC 6397
• Lithium Depletion in Pre-Mainsequence Solar-Like Stars
• WIYN Open Cluster Study 1: Deep Photometry of NGC 188
• UVES Be observations of early-G dwarfs in old clusters

Cited by in corpus (32)

• Time scales of Li evolution: a homogeneous analysis of open clusters from ZAMS to late-MS
• On the metallicity of open clusters. III. Homogenised sample
• Chemical abundance analysis of the Open Clusters Cr110, NGC2099 (M37), NGC2420, NGC7789 and M67 (NGC2682)
• Element abundances of unevolved stars in the open cluster M 67
• Chemical abundance analysis of the Open Clusters Berkeley 32, NGC 752, Hyades and Praesepe
• A Chemical Abundance Study of 10 Open Clusters Based on WIYN-Hydra Spectroscopy
• Li depletion in solar analogues with exoplanets: Extending the sample
• On the metallicity of open clusters II. Spectroscopy
• Open clusters as key tracers of Galactic chemical evolution. III. Element abundances in Berkeley 20, Berkeley 29, Collinder 261, and Melotte 66
• Models for Solar Abundance Stars with Gravitational Settling and Radiative Accelerations: Application to M67 and NGC188
• Age and distance for the old open cluster NGC188 from the eclipsing binary member V12
• The Gaia-ESO survey: mapping the shape and evolution of the radial abundance gradients with open clusters
• A Tale of Two Anomalies: Depletion, Dispersion, and the Connection Between the Stellar Lithium Spread and Inflated Radii on the Pre-Main Sequence
• The Gaia-ESO Survey: Empirical estimates of stellar ages from lithium equivalent widths (EAGLES)
• Lithium evolution in intermediate age and old open clusters: NGC 752 revisited
• Lithium in M67: From the main sequence to the red giant branch
• Metallicities, Age--Metallicity relationships, and Kinematics of Red Giant Branch Stars in the Outer Disk of the Large Magellanic Cloud
• The Age of the Oldest Stars in the Local Galactic Disk From Hipparcos Parallaxes of G and K Subgiants
• Li Evolution and the Open Cluster NGC 6819: A Correlation Between Li Depletion and Spindown in Dwarfs More Massive Than the F-Dwarf Li-Dip
• Using rotation, magnetic activity and lithium to estimate the ages of low mass stars
• Planetary systems around close binary stars: the case of the very dusty, Sun-like, spectroscopic binary BD+20 307
• Lithium abundance in the metal-poor open cluster NGC 2243
• Beryllium anomalies in solar-type field stars
• The Old, Super-Metal-Rich Open Cluster, NGC 6791 - Elemental Abundances in Turn-off Stars from Keck/HIRES Spectra
• A Survey of Open Clusters in the u'g'r'i'z' Filter System: III. Results for the Cluster NGC 188
• Mapping radial abundance gradients with Gaia-ESO open clusters: Evidence of recent gas accretion in the Milky Way disk
• WIYN Open Cluster Study: The Old Open Cluster, NGC 188, and a Re-evaluation of Lithium-Richness Among Red Giants
• 2MASS photometry and kinematical studies of open cluster NGC 188
• Systematic Differences in Spectroscopic Analysis of Red Giants
• Lithium depletion in solar analogs: age and mass effects
• Lithium abundances in the old open cluster NGC 3960 from VLT/FLAMES observations
• Membership and lithium in the old, metal-poor open cluster Berkeley 32