Magnetic Fields of M Dwarfs from the Pleiades Open Cluster

Abstract

Average magnetic field measurements are presented for 62 M-dwarf members of the Pleiades open cluster, derived from Zeeman-enhanced Fe I lines in the H-band. An MCMC methodology was employed to model magnetic filling factors using SDSS-IV APOGEE high-resolution spectra, along with the radiative transfer code SYNMAST, MARCS stellar atmosphere models, and the APOGEE DR17 spectral line list. There is a positive correlation between mean magnetic fields and stellar rotation, with slow-rotator stars (Rossby number, Ro$>$0.13) exhibiting a steeper slope than rapid-rotators (Ro$<$0.13). However, the latter sample still shows a positive trend between Ro and magnetic fields, which is given by $<$B$>$ = 1604 $\times$ Ro${}^{-0.20}$. The derived stellar radii, when compared with physical isochrones, show that on average, our sample shows radius inflation, with median enhanced radii ranging from +3.0$\%$ to +7.0$\%$, depending on the model. There is a positive correlation between magnetic field strength and radius inflation, as well as with stellar spot coverage, correlations that together indicate that stellar spot-filling factors generated by strong magnetic fields might be the mechanism that drives radius inflation in these stars. We also compare our derived magnetic fields with chromospheric emission lines (H$\alpha$, H$\beta$ and Ca II K), as well as with X-ray and H$\alpha$ to bolometric luminosity ratios, and find that stars with higher chromospheric and coronal activity tend to be more magnetic.

Accepted for publication by The Astrophysical Journal (ApJ); doi:10.3847/1538-4357/ad571f

References in corpus (32)

• Array Programming with NumPy
• 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
• Painting a portrait of the Galactic disc with its stellar clusters
• The Second-Generation Guide Star Catalog: Description and Properties
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• The Magnetic Fields of Classical T Tauri Stars
• Kepler Flares I. Active and Inactive M dwarfs
• Evolution of low-mass star and brown dwarf eclipsing binaries
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
• Magnetic fields of M dwarfs
• Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar Candidate Members
• Strong dipole magnetic fields in fast rotating fully convective stars
• Magnetic fields in M dwarfs from the CARMENES survey
• The global and small-scale magnetic fields of fully convective, rapidly spinning M dwarf pair GJ65A and B
• Stellar activity with LAMOST - II. Chromospheric activity in open clusters
• 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
• Magnetic Field of the Eclipsing M Dwarf Binary YY Gem
• Starspots and Magnetism: Testing the Activity Paradigm in the Pleiades and M67
• Magnetic Properties of Young Stars in the TW Hydrae Association
• Constraining atmospheric parameters and surface magnetic fields with $\text{ZeeTurbo}$: an application to SPIRou spectra
• The X-ray luminosity function of M37 and the evolution of coronal activity in low-mass stars
• Small-scale magnetic fields of the spectroscopic binary T Tauri stars V1878 Ori and V4046 Sir

Cited by in corpus (1)

• LAMOST medium-resolution observations of the Pleiades