The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in low-mass pre-main-sequence stars

Abstract

We show that non-magnetic models for the evolution of pre-main-sequence (PMS) stars *cannot* simultaneously describe the colour-magnitude diagram (CMD) and the pattern of lithium depletion seen in the cluster of young, low-mass stars surrounding ${\gamma }^2$ Velorum. The age of 7.5+/-1 Myr inferred from the CMD is much younger than that implied by the strong Li depletion seen in the cluster M-dwarfs and the Li depletion occurs at much redder colours than predicted. The epoch at which a star of a given mass depletes its Li and the surface temperature of that star are both dependent on its radius. We demonstrate that if the low-mass stars have radii ~10 per cent larger at a given mass and age, then both the CMD and Li depletion pattern of the Gamma Vel cluster are explained at a common age of 18-21 Myr. This radius inflation could be produced by some combination of magnetic suppression of convection and extensive cool starspots. Models that incorporate radius inflation suggest that PMS stars similar to those in the Gamma Vel cluster, in the range 0.2<M/Msun<0.7, are at least a factor of two older and ~7 per cent cooler than previously thought and that their masses are much larger (by >30 per cent) than inferred from conventional, non-magnetic models in the Hertzsprung-Russell diagram. Systematic changes of this size may be of great importance in understanding the evolution of young stars, disc lifetimes and the formation of planetary systems.

10 pages, accepted for publication in MNRAS

References in corpus (15)

• The Dartmouth Stellar Evolution Database
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Improving PARSEC models for very low mass stars
• The stellar association around Gamma Velorum and its relationship with Vela OB2
• Absolute properties of the low-mass eclipsing binary CM Draconis
• The effect of activity on stellar temperatures and radii
• BANYAN. IV. Fundamental parameters of low-mass star candidates in nearby young stellar kinematic groups - Isochronal Age determination using Magnetic evolutionary models
• Older and Colder: The impact of starspots on pre-main sequence stellar evolution
• Magnetic Inhibition of Convection and the Fundamental Properties of Low-Mass Stars. II. Fully Convective Main Sequence Stars
• The Gaia-ESO Survey: Chromospheric Emission, Accretion Properties, and Rotation in $\gamma$ Velorum and Chamaeleon I
• Rotation, inflation, and lithium in the Pleiades
• The effect of starspots on the radii of low-mass pre-main sequence stars
• The effect of starspots on the ages of low-mass stars determined from the lithium depletion boundary
• The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster Gamma Velorum
• Dynamical masses of the low-mass stellar binary ABDoradusB

Cited by in corpus (41)

• Painting a portrait of the Galactic disc with its stellar clusters
• Age determination for 269 $Gaia$ DR2 Open Clusters
• The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
• The SPOTS Models: A Grid of Theoretical Stellar Evolution Tracks and Isochrones For Testing The Effects of Starspots on Structure and Colors
• The Gaia-ESO Survey: Empirical estimates of stellar ages from lithium equivalent widths (EAGLES)
• A Measurement of Radius Inflation in the Pleiades and its Relation to Rotation and Lithium Depletion
• The Gaia-ESO Survey: Membership probabilities for stars in 63 open and 7 globular clusters from 3D kinematics
• The effects of rotation on the lithium depletion of G- and K-dwarfs in Messier 35
• Light Elements in the Universe
• Low mass young stars in the Milky Way unveiled by DBSCAN and Gaia EDR3. Mapping the star forming regions within 1.5 Kpc
• M Dwarf rotation from the $K2$ young clusters to the field. I. A Mass-Rotation Correlation at 10 Myr
• The Gaia-ESO Survey: Membership probabilities for stars in 32 open clusters from 3D kinematics
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- III. Exploring the properties of young associations through their variables, dippers, and candidate exoplanets
• MESA models with magnetic braking
• The Evolution Of The Inner Regions of Protoplanetary Disks
• Gaia-ESO Survey: Role of magnetic activity and starspots on pre-main sequence lithium evolution
• Disruption of Hierarchical Clustering in the Vela OB2 Complex and the Cluster Pair Collinder 135 and UBC7 with Gaia EDR3: Evidence of Supernova Quenching
• Metallicity and age effects on lithium depletion in solar analogues
• System IMF of the 25 Ori Group from Planetary-Mass Objects to Intermediate/High-Mass Stars
• The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232
• Chronostar. II. Kinematic age and substructure of the Scorpius-Centaurus OB2 association
• The Multiplicity of M-Dwarfs in Young Moving Groups
• Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25
• The dynamics of the γ Vel cluster and nearby Vela OB2 association
• Dynamical Masses of Young Stars II: Young Taurus Binaries Hubble~4, FF~Tau, and HP~Tau/G3
• Multiple kinematical populations in Vela OB2 from Gaia DR1 data
• The Gaia-ESO Survey: Constraining evolutionary models and ages for young low mass stars with measurements of lithium depletion and rotation
• The Structure and 3D Kinematics of Vela OB2
• Statistical Fitting of Evolution Models to Rotation Rates of Sun-Like Stars
• Lithium in coalesced non-compact stars
• A Study of Stellar Spins in 15 Open Clusters
• Nearby Young, Active, Late-type Dwarfs in Gaia's First Data Release
• Characterizing the stellar population of NGC 1980
• Estimating the ages of open star clusters from properties of their extended tidal tails
• Empirical Determination of the Lithium 6707.856 Å Wavelength in Young Stars
• Searching for new young stars in the northern hemisphere: The Pisces Moving Group
• TIC 43152097. The first eclipsing binary in NGC 2232
• V410 Puppis: A useful laboratory for early stellar evolution
• Standing torsional Alfvén waves as the source of the rotational period variation in magnetic early-type stars
• Using a neural network approach and starspots dependent models to predict effective temperatures and ages of young stars
• Transit Hunt for Young and Maturing Exoplanets (THYME) VIII: a Pleiades-age association harboring two transiting planetary systems from Kepler