Stellar Characterization and Radius Inflation of Hyades M Dwarf Stars From the APOGEE Survey

Abstract

We present a spectroscopic analysis of a sample of 48 M dwarf stars ($0.2M_{\odot }<M<0.6M_{\odot }$) from the Hyades open cluster using high-resolution H-band spectra from the SDSS/APOGEE survey. Our methodology adopts spectrum synthesis with LTE MARCS model atmospheres, along with the APOGEE DR17 line list, to determine effective temperatures, surface gravities, metallicities, and projected rotational velocities. The median metallicity obtained for the Hyades M dwarfs is [M/H]= 0.09$\pm$0.03 dex, indicating a small internal uncertainty and good agreement with optical results for Hyades red-giants. Overall, the median radii are larger than predicted by stellar models by 1.6$\pm$2.3\% and 2.4$\pm$2.3\%, relative to a MIST and DARTMOUTH isochrone, respectively. We emphasize, however, that these isochrones are different and the fractional radius inflation for the fully- and partially-convective regimes have distinct behaviors depending on the isochrone. Using a MIST isochrone there is no evidence of radius inflation for the fully convective stars, while for the partially convective M-dwarfs the radii are inflated by 2.7$\pm$2.1\%, which is in agreement with predictions from models that include magnetic fields. For the partially-convective stars, rapid-rotators present on average higher inflation levels than slow-rotators. The comparison with SPOTS isochrone models indicates that the derived M dwarf radii can be explained by accounting for stellar spots in the photosphere of the stars, with 76\% of the studied M dwarfs having up to 20\% spot coverage, and the most inflated stars with $\sim$20 -- 40\% spot coverage.

Accepted for publication by The Astrophysical Journal (ApJ)

References in corpus (50)

• Array Programming with NumPy
• The Gaia mission
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The 2.5 m Telescope of the Sloan Digital Sky Survey
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The Dartmouth Stellar Evolution Database
• The K2 Mission: Characterization and Early results
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
• Basic physical parameters of a selected sample of evolved stars
• Unresolved stellar companions with Gaia DR2 astrometry
• Evolution of low-mass star and brown dwarf eclipsing binaries
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• The Stellar Populations of Praesepe and Coma Berenices
• Target Selection for the SDSS-IV APOGEE-2 Survey
• Precise radial velocities of giant stars. III. Spectroscopic stellar parameters
• PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
• The Open Cluster Chemical Abundances and Mapping Survey: IV. Abundances for 128 Open Clusters using SDSS/APOGEE DR16
• CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions
• The APOGEE Data Release 16 Spectral Line List
• K2 rotation periods for low-mass Hyads and a quantitative comparison of the distribution of slow rotators in the Hyades and Praesepe
• Elemental abundances in the atmosphere of clump giants
• Older and Colder: The impact of starspots on pre-main sequence stellar evolution
• The SPOTS Models: A Grid of Theoretical Stellar Evolution Tracks and Isochrones For Testing The Effects of Starspots on Structure and Colors
• Reevaluating the Mass-Radius Relation for Low-Mass, Main Sequence Stars
• The CARMENES search for exoplanets around M dwarfs. Stellar atmospheric parameters of target stars with SteParSyn
• Final Targeting Strategy for the SDSS-IV APOGEE-2N Survey
• The CARMENES search for exoplanets around M dwarfs -- Photospheric parameters of target stars from high-resolution spectroscopy. II. Simultaneous multiwavelength range modeling of activity insensitive lines
• Chemical Abundances of Main-Sequence, Turnoff, Subgiant and red giant Stars from APOGEE spectra II: Atomic Diffusion in M67 Stars
• A Measurement of Radius Inflation in the Pleiades and its Relation to Rotation and Lithium Depletion
• Chemical (in)homogeneity and atomic diffusion in the open cluster M67
• Temperatures and Metallicities of M dwarfs in the APOGEE Survey
• Chemical Abundances of M-dwarfs from the APOGEE Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186
• Stellar Characterization of M-dwarfs from the APOGEE Survey: A Calibrator Sample for the M-dwarf Metallicities
• A physically motivated and empirically calibrated method to measure effective temperature, metallicity, and Ti abundance of M dwarfs
• Detailed Chemical Abundances for a Benchmark Sample of M Dwarfs from the APOGEE Survey
• Starspots and Magnetism: Testing the Activity Paradigm in the Pleiades and M67
• Metallicity determination of M dwarfs - Expanded parameter range in metallicity and effective temperature
• The CARMENES search for exoplanets around M dwarfs -- A deep learning approach to determine fundamental parameters of target stars
• The Near-Ultraviolet Luminosity Function of Young, Early M-Type Dwarf Stars
• Gaia Gaps and the Physics of Low-Mass Stars. I. The Fully Convective Boundary
• Magnetic Inflation and Stellar Mass I: Revised Parameters for the Component Stars of the Kepler Low-mass Eclipsing Binary T-Cyg1-12664
• Spectroscopic study of solar twins and analogues
• Determination of spectroscopic parameters for 313 M dwarf stars from their APOGEE Data Release 16 H-band spectra
• Effective Temperatures of Low-Mass Stars from High-Resolution H-band Spectroscopy
• A metallicity study of F, G, K and M dwarfs in the Coma Berenices open cluster from the APOGEE survey
• The X-ray view of the Hyades cluster: updated
• Estimating $T_{\mathrm{eff}}$, radius and luminosity of M-dwarfs using high resolution optical and NIR spectral features
• Evidence of radius inflation in stars approaching the slow-rotator sequence
• Spectroscopic Determination of Stellar Parameters and Oxygen Abundances for Hyades/Field G-K Dwarfs

Cited by in corpus (2)

• Magnetic Fields of M Dwarfs from the Pleiades Open Cluster
• Five new eclipsing binaries with low-mass companions