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

Abstract

Spectroscopy of 333 NGC 6819 stars and Gaia astrometry are used to map Li evolution from the giant branch tip to 0.5 mag below the Li dip. Isochrone comparison with [Fe/H] = -0.04, based upon neural network spectroscopic analysis, produces an age of 2.25 (2.4) Gyr for E(B-V) = 0.16 (0.14) and (m-M) = 12.40 (12.29). Despite originating outside the Li dip, only 10% of single subgiants/giants have measurable Li. Above the Li dip, the limiting A(Li) for single stars is 3.2 +/- 0.1 but the lower range is comparable to that found within the dip. The F-dwarf Li dip profile agrees with the Hyades/Praesepe, evolved forward. The Li level among stars populating the plateau fainter than the Li dip is A(Li) = 2.83 +/- 0.16; the dispersion is larger than expected from spectroscopic error alone. Comparison of Li and V_ROT distributions among turnoff stars in NGC 7789, NGC 2506, NGC 3680, and NGC 6819 indicates that rotational spindown from the main sequence is critical in defining the boundaries of the Li dip. For higher mass dwarfs, spindown is likewise correlated with Li depletion, creating a second dip, but at higher mass and on a longer time scale. The Li distribution among evolved stars of NGC 6819 is more representative of the older M67, where subgiant and giant stars emerge from within the Li dip, than the younger NGC 7789, where a broad range in V_ROT among the turnoff stars likely produces a range in mass among the giants.

arXiv comment28 pages, 12 figures; accepted for publication in AJ

References in corpus (133)

• The chemical composition of the Sun
• Gaia Data Release 2. Summary of the contents and survey properties
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The Dartmouth Stellar Evolution Database
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• On the rotational evolution of solar- and late-type stars, its magnetic origins, and the possibility of stellar gyrochronology
• A Gaia DR2 view of the Open Cluster population in the Milky Way
• Milky Way Cepheid Standards for Measuring Cosmic Distances and Application to Gaia DR2: Implications for the Hubble Constant
• The effective temperature scale of FGK stars. II. Teff : color : [Fe/H] calibrations
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• The Victoria-Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting
• Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology
• The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
• Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
• Testing a Predictive Theoretical Model for the Mass Loss Rates of Cool Stars
• Time scales of Li evolution: a homogeneous analysis of open clusters from ZAMS to late-MS
• A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster
• Synthetic Stellar Photometry - I. General considerations and new transformations for broad-band systems
• The rotation and Galactic kinematics of mid M dwarfs in the Solar Neighborhood
• Thermohaline instability and rotation-induced mixing. I - Low- and intermediate-mass solar metallicity stars up to the end of the AGB
• Rotational velocities of A-type stars IV. Evolution of rotational velocities
• Signatures of intrinsic Li depletion and Li-Na anti-correlation in the metal-poor globular cluster NGC6397
• Stellar Models with Microscopic Diffusion and Rotational Mixing I: Application to the Sun
• The Kepler Cluster Study: Stellar Rotation in NGC6811
• Rotational velocities of A-type stars. III. Velocity distributions
• Stellar Rotation Periods of the Kepler Objects of Interest: A Dearth of Close-in Planets around Fast Rotators
• Rotational velocities of A-type stars II. Measurement of vsini in the northern hemisphere
• Stellar Rotation in M35: Mass-Period Relations, Spin-Down Rates, and Gyrochronology
• Lithium abundances in nearby FGK dwarf and subgiant stars: internal destruction, Galactic chemical evolution, and exoplanets
• Hydrodynamical stellar models including rotation, internal gravity waves and atomic diffusion. I. Formalism and tests on Pop I dwarfs
• A double main sequence turn-off in the rich star cluster NGC 1846 in the Large Magellanic Cloud
• Radius Dependent Angular Momentum Evolution in Low-Mass Stars. I
• Metal Abundances of Red Clump Stars in Open Clusters: I. NGC 6819
• Rotation, differential rotation, and gyrochronology of active Kepler stars
• Angular Momentum Loss from Cool Stars: An Empirical Expression and Connection to Stellar Activity
• Multiple stellar populations in three rich Large Magellanic Cloud star clusters
• Confirmation of the $Gaia$ DR2 parallax zero-point offset using asteroseismology and spectroscopy in the $Kepler$ field
• A secondary clump of red giant stars: why and where
• Standard big bang nucleosynthesis and primordial CNO Abundances after Planck
• The Age and Age Spread of the Praesepe and Hyades Clusters: a Consistent, ~800 Myr Picture from Rotating Stellar Models
• The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr)
• The Revolution Revolution: magnetic morphology driven spin-down
• The Color-Period Diagram and Stellar Rotational Evolution - New Rotation Period Measurements in the Open Cluster M34
• Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters: A Correlation Between Turnoff Width and Early Escape Velocity
• Rotating models of young solar-type stars : Exploring braking laws and angular momentum transport processes
• Bayesian Ages for Early-Type Stars from Isochrones Including Rotation, and a Possible Old Age for the Hyades
• The Bologna Open Cluster Chemical Evolution (BOCCE) Project: midterm results from the photometric sample
• WIYN Open Cluster Study. LXXV. Testing the Metallicity Dependence of Stellar Lithium Depletion Using Hyades-Aged Clusters. 1. Hyades & Praesepe
• Stroemgren survey for Asteroseismology and Galactic Archaeology: let the SAGA begin
• A path towards understanding the rotation-activity relation of M dwarfs with K2 mission, X-ray and UV data
• Lithium abundances for 185 main-sequence stars - Galactic evolution and stellar depletion of lithium
• NGC 6819: testing the asteroseismic mass scale, mass loss, and evidence for products of non-standard evolution
• Angular Momentum Transport by Internal Gravity Waves. I - Pop I Main Sequence Stars
• An asteroseismic membership study of the red giants in three open clusters observed by Kepler: NGC6791, NGC6819, and NGC6811
• Detailed chemical composition of the open cluster IC 4651: The iron peak, alpha elements, and Li
• Rotational velocities of A-type stars I. Measurement of vsini in the southern hemisphere
• On Lithium-Rich Red Giants. I. Engulfment of Sub-Stellar Companions
• Apparent Age Spreads in Clusters and the Role of Stellar Rotation
• Discovery of two distinct red clumps in NGC419: a rare snapshot of a cluster at the onset of degeneracy
• The lithium-rotation connection in the 125 Myr-old Pleiades cluster
• Population Parameters of Intermediate-Age Star Clusters in the Large Magellanic Cloud. I. NGC 1846 and its Wide Main Sequence Turnoff
• WIYN Open Cluster Study. XXIV. Stellar Radial-Velocity Measurements in NGC 6819
• Population Parameters of Intermediate-Age Star Clusters in the Large Magellanic Cloud. II. New Insights from Extended Main Sequence Turnoffs in 7 Star Clusters
• Chemical Abundances of Main-Sequence, Turnoff, Subgiant and red giant Stars from APOGEE spectra II: Atomic Diffusion in M67 Stars
• Rotation, inflation, and lithium in the Pleiades
• The rotation of field stars from CoRoT data
• The UBV(RI)c colors of the Sun
• Beryllium in the Hyades F and G Dwarfs from Keck/HIRES Spectra
• Rotating Stellar Models Can Account for the Extended Main Sequence Turnoffs in Intermediate Age Clusters
• Results of a Search for gamma Dor and delta Sct Stars with the Kepler Spacecraft
• WIYN Open Cluster Study. LX. Spectroscopic Binary Orbits in NGC 6819
• The Metastable Dynamo Model of Stellar Rotational Evolution
• Can rotation explain the multiple main sequence turn-offs of Magellanic Cloud star clusters?
• A Tale of Two Anomalies: Depletion, Dispersion, and the Connection Between the Stellar Lithium Spread and Inflated Radii on the Pre-Main Sequence
• Detection of a large sample of Gamma Dor stars from Kepler space photometry and high-resolution ground-based spectroscopy
• The effects of rotation on the main-sequence turnoff of intermediate-age massive star clusters
• The search for multiple populations in Magellanic Cloud Clusters IV: Coeval multiple stellar populations in the young star cluster NGC 1978
• Lithium in the Intermediate-Age Open Cluster, NGC 3680
• The inflated radii of M-dwarfs in the Pleiades
• Atomic Diffusion and Mixing in Old Stars. III. Analysis of NGC 6397 Stars under New Constraints
• Atomic diffusion and mixing in old stars IV: Weak abundance trends in the globular cluster NGC 6752
• The dependence of stellar mass and angular momentum losses on latitude and on active region and dipolar magnetic fields
• WIYN Open Cluster Study. XXXVIII. Stellar Radial Velocities in the Young Open Cluster M35 (NGC 2168)
• The exclusion of a significant range of ages in a massive star cluster
• Boron Depletion in F and G Dwarf Stars and the Beryllium-Boron Correlation
• Rotation and activity in the solar-metallicity open cluster NGC2516
• The Gaia-ESO Survey: Evidence of atomic diffusion in M67?
• Lithium in M67: From the main sequence to the red giant branch
• The GALAH Survey: Verifying abundance trends in the open cluster M67 using non-LTE spectroscopy
• Atomic Diffusion and Mixing in Old Stars V: A deeper look into the Globular Cluster NGC 6752
• The Open Cluster NGC 7789: II. CCD VI Photometry
• A Young Cluster With an Extended Main Sequence Turnoff: Confirmation of a Prediction of the Stellar Rotation Scenario
• Extended Main Sequence Turnoffs in Intermediate-Age Star Clusters: Stellar Rotation diminishes, but does not eliminate, Age Spreads
• Membership, metallicity and lithium abundances for solar-type stars in NGC 6633
• WIYN/Hydra Detection of Lithium Depletion in F Stars of the Young Open Cluster M35 and Implications for the Development of the Lithium Gap
• Atomic diffusion and mixing in old stars VI: The lithium content of M30
• A Lithium-Rich Red Giant Below the Clump in the Kepler Cluster, NGC 6819
• Evolution of lithium beyond the solar age: a Li survey of the old open cluster NGC 188
• WOCS 40007: A Detached Eclipsing Binary near the Turnoff of the Open Cluster NGC 6819
• Lithium depletion is a strong test of core-envelope recoupling
• Boron Abundances Across the "Li-Be Dip" in the Hyades
• A Long-Period Totally Eclipsing Binary Star at the Turnoff of the Open Cluster NGC 6819 Discovered with Kepler
• Determining the Age of the Kepler Open Cluster NGC 6819 With a New Triple System and Other Eclipsing Binary Stars
• Gaia Data Release 2: Rotational modulation in late-type dwarfs
• Lithium Abundances of the Super-Metal-Rich Open Cluster NGC 6253
• Tracing mixing in stars: new beryllium observations of the open clusters NGC 2516, Hyades, and M67
• Spectroscopic Abundances in the Open Cluster, NGC 6819
• Lithium abundance and rotation of seismic solar analogues - Solar and stellar connection from Kepler and Hermes observations
• Controversial Age Spreads from the Main Sequence Turn-Off and Red Clump in Intermediate-Age Clusters in the LMC
• WIYN Open Cluster Study : Wide-Field CCD Photometry of the Old Open Cluster NGC 6819
• WIYN Open Cluster Study. XXXIX. Abundances in NGC 6253 from HYDRA Spectroscopy of the Li 6708 A Region
• On the Interpretation of Sub-Giant Branch Morphologies of Intermediate-Age Star Clusters with Extended Main Sequence Turnoffs
• A uvbyCaHbeta Analysis of the Old Open Cluster, NGC 6819
• Shallow extra mixing in solar twins inferred from Be abundances
• WIYN Open Cluster Study, LXXVI. Li Evolution Among Stars of Low/Intermediate Mass: The Metal-Deficient Open Cluster, NGC 2506
• Asteroseismic Study on Cluster Distance Moduli for RGB Stars in NGC 6791 and NGC 6819
• The Puzzling Li-rich Red Giant Associated with NGC 6819
• Evolution of lithium abundance in the Sun and solar twins
• New asteroseismic scaling relations based on Hayashi track relation applied to red-giant branch stars in NGC 6791 and NGC 6819
• A uvbyCaHbeta CCD Analysis of the Open Cluster Standard, NGC 752
• Li in Open Clusters: Cool Dwarfs in the Young, Subsolar Metallicity Cluster M35 (NGC 2168)
• Dynamics of Turbulent Convection and Convective Overshoot in a Moderate Mass Star
• Systematic Differences in Spectroscopic Analysis of Red Giants
• The radial distributions of the two main-sequence components in the young massive star cluster NGC 1856
• WIYN Open Cluster Study. LXXII. A uvbyCa Hbeta CCD Analysis of the Metal-Deficient Open Cluster, NGC 2506
• The effects of the overshooting of the convective core on main-sequence turnoffs of young- and intermediate-age star clusters
• First Observational Signature of Rotational Deceleration in a Massive, Intermediate-age Star Cluster in the Magellanic Clouds
• Stellar variability at the main-sequence turnoff of the intermediate-age LMC cluster NGC 1846
• The Unevolved Main Sequence of Nearby Field Stars and the Open Cluster Distance Scale
• Lithium enhancement in X-ray binaries due to stellar rotation
• The Effects of Binary Stars on the Color-Magnitude Diagrams of Young-Age Massive Star Clusters
• A Spectroscopic Analysis of the Eclipsing Short-Period Binary v505 Per and the Origin of the Lithium Dip

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