Older and Colder: The impact of starspots on pre-main sequence stellar evolution

Abstract

We assess the impact of starspots on the evolution of late-type stars during the pre-main sequence (pre-MS) using a modified stellar evolution code. We find that heavily spotted models of mass 0.1-1.2\msun\ are inflated by up to $10$% during the pre-MS, and up to 4% and 9% for fully- and partially-convective stars at the zero-age MS, consistent with measurements from active eclipsing binary systems. Spots similarly decrease stellar luminosity and $T_{\mathrm{eff}}$, causing isochrone-derived masses to be under-estimated by up to a factor of $2\times$, and ages to be under-estimated by a factor of 2-10$\times$, at 3 Myr. Consequently, pre-MS clusters and their active stars are systematically older and more massive than often reported. Cluster ages derived with the lithium depletion boundary technique are erroneously young by $\sim 15$% and $10$% at $30$ and $100$ Myr respectively, if 50% spotted stars are interpreted with un-spotted models. Finally, lithium depletion is suppressed in spotted stars with radiative cores, leading to a fixed-temperature lithium dispersion on the MS if a range of spot properties are present on the pre-MS. Such dispersions are large enough to explain Li abundance spreads seen in young open clusters, and imply a range of radii at fixed mass and age during the pre-MS Li burning epoch. By extension, this implies that mass, composition, and age do not uniquely specify the HR diagram location of pre-MS stars.

16 pages, 8 figures, accepted to ApJ. For a brief video discussing the main results, see https://www.youtube.com/watch?v=IA7WUeqIFug

References in corpus (15)

• Evolution of low-mass star and brown dwarf eclipsing binaries
• The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones
• 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
• Reevaluating the Mass-Radius Relation for Low-Mass, Main Sequence Stars
• Magnetic Inhibition of Convection and the Fundamental Properties of Low-Mass Stars. II. Fully Convective Main Sequence Stars
• A Surprising Reversal of Temperatures in the Brown-Dwarf Eclipsing Binary 2MASS J05352184-0546085
• Self-Consistent Magnetic Stellar Evolution Models of the Detached, Solar-Type Eclipsing Binary EF Aquarii
• Rotation, inflation, and lithium in the Pleiades
• IN-SYNC I: Homogeneous Stellar Parameters from High Resolution APOGEE Spectra for Thousands of Pre-main Sequence Star
• The effect of starspots on the radii of low-mass pre-main sequence stars
• OPserver: interactive online-computations of opacities and radiative accelerations
• The effect of starspots on the ages of low-mass stars determined from the lithium depletion boundary
• New BVIc Photometry of Low-mass Pleiades Stars: Exploring the Effects of Rotation on Broadband Colors
• The Impact of Chromospheric Activity on Observed Initial Mass Functions

Cited by in corpus (59)

• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• A Guide to Realistic Uncertainties on Fundamental Properties of Solar-Type Exoplanet Host Stars
• Empirical, Accurate Masses and Radii of Single Stars with TESS and Gaia
• Placing the spotted T Tauri star LkCa 4 on an HR diagram
• No Sun-like dynamo on the active star $\zeta$ Andromedae from starspot asymmetry
• Age Determination in Upper Scorpius with Eclipsing Binaries
• An extensive VLT/X-Shooter library of photospheric templates of pre-main sequence stars
• The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in low-mass pre-main-sequence stars
• A Measurement of Radius Inflation in the Pleiades and its Relation to Rotation and Lithium Depletion
• Stellar Rotation in the Gaia Era: Revised Open Clusters Sequences
• Stellar Rotation of T Tauri stars in the Orion Star-Forming Complex
• The effects of rotation on the lithium depletion of G- and K-dwarfs in Messier 35
• Starspots and Magnetism: Testing the Activity Paradigm in the Pleiades and M67
• Contemporaneous Imaging Comparisons of the Spotted Giant $\sigma$ Geminorum Using Interferometric, Spectroscopic, and Photometric Data
• An Improved HR Diagram for the Orion Trapezium Cluster
• M Dwarf rotation from the $K2$ young clusters to the field. I. A Mass-Rotation Correlation at 10 Myr
• Gaia Gaps and the Physics of Low-Mass Stars. I. The Fully Convective Boundary
• MESA models with magnetic braking
• The Factory and the Beehive III: PTFEB132.707+19.810, a Low-Mass Eclipsing Binary in Praesepe Observed by PTF and K2
• Gaia-ESO Survey: Role of magnetic activity and starspots on pre-main sequence lithium evolution
• BEAST begins: Sample characteristics and survey performance of the B-star Exoplanet Abundance Study
• Age spreads and the temperature dependence of age estimates in Upper Sco
• Metallicity and age effects on lithium depletion in solar analogues
• Age Spreads and Systematics in λ Orionis with Gaia DR2 and the SPOTS tracks
• The Anatomy of an Unusual Edge-on Protoplanetary Disk. II. Gas temperature and a warm outer region
• Chronostar. II. Kinematic age and substructure of the Scorpius-Centaurus OB2 association
• Isochronal age-mass discrepancy of young stars: SCExAO/CHARIS integral field spectroscopy of the HIP 79124 triple system
• Dynamical Masses and Stellar Evolutionary Model Predictions of M-Stars
• The ASAS-SN Catalog of Variable Stars VIII: "Dipper" Stars in the Lupus Star-Forming Region
• Magnetic Activity-Rotation-Age-Mass Relations in Late Pre-main Sequence Stars
• WIYN Open Cluster Study 89. M48 (NGC 2548) 2: Lithium Abundances in the 420 Myr Open Cluster M48 From Giants Through K Dwarfs
• HST survey of the Orion Nebula Cluster in the H${}_2$O 1.4 $\mu$m absorption band: II. The substellar IMF down to planetary masses
• Stellar Characterization and Radius Inflation of Hyades M Dwarf Stars From the APOGEE Survey
• Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit and Discovery of a CO Outflow
• Rotation at the Fully Convective Boundary: Insights from Wide WD + MS Binary Systems
• NGTS clusters survey -- III: A low-mass eclipsing binary in the Blanco 1 open cluster spanning the fully convective boundary
• Dynamical Surface Imaging of lambda Andromedae
• A Study of Stellar Spins in 15 Open Clusters
• Projected Rotational Velocities and Fundamental Properties of Low-Mass Pre-Main Sequence Stars in the Taurus-Auriga Star Forming Region
• Observationally Constraining the Starspot Properties of Magnetically Active M67 Sub-Subgiant S1063
• Evidence of radius inflation in stars approaching the slow-rotator sequence
• THOR 42: A touchstone $\sim$24 Myr-old eclipsing binary spanning the fully-convective boundary
• A Low-Mass Pre-Main-Sequence Eclipsing Binary in Lower Centaurus Crux Discovered with TESS
• Theoretical predictions of surface light element abundances in protostellar and pre-Main Sequence phase
• LAMOST medium-resolution observations of the Pleiades
• Evidence of a substellar companion to AB Dor C
• Fundamental properties of the pre-main sequence eclipsing stars of MML 53 and the mass of the tertiary
• A Low-mass, Pre-main-sequence Eclipsing Binary in the 40 Myr Columba Association -- Fundamental Stellar Parameters and Modeling the Effect of Star Spots
• Eclipsing binaries in the open cluster Ruprecht 147. IV: The active triple system EPIC 219511354
• A young spectroscopic binary in a quintuple system part of the Local Association
• Young, active radio stars in the AB Doradus moving group
• Walking the Line: Young Stars on the Boundary of the Epsilon Cha and Lower Centaurus-Crux Associations
• Characterization of low-mass companions to $\text{Kepler}$ objects of interest observed with APOGEE-N
• ACRONYM IV: Three New, Young, Low-mass Spectroscopic Binaries
• NGC 3105: A Young Cluster in the Outer Galaxy
• Suppression of lithium depletion in young low-mass stars from fast rotation
• Constraints on star formation in Orion A from Gaia
• Haffner 16 Redux: Revisiting a Young Cluster in the Outer Galaxy
• Twinkle Twinkle Little Star, Roman Sees Where You Are: Predicting Exoplanet Transit Yields in the Rosette Nebula with the Nancy Grace Roman Space Telescope