How to Constrain Your M Dwarf. II. The Mass–Luminosity–Metallicity Relation from 0.075 to 0.70 Solar Masses

Abstract

The mass-luminosity relation for late-type stars has long been a critical tool for estimating stellar masses. However, there is growing need for both a higher-precision relation and a better understanding of systematic effects (e.g., metallicity). Here we present an empirical relationship between M K S and M * spanning 0.075M < M * < 0.70M . The relation is derived from 62 nearby binaries, whose orbits we determine using a combination of Keck/NIRC2 imaging, archival adaptive optics data, and literature astrometry. From their orbital parameters, we determine the total mass of each system, with a precision better than 1% in the best cases. We use these total masses, in combination with resolved K S magnitudes and system parallaxes, to calibrate the M K S -M * relation. The resulting posteriors can be used to determine masses of single stars with a precision of 2-3%, which we confirm by testing the relation on stars with individual dynamical masses from the literature. The precision is limited by scatter around the best-fit relation beyond measured M * uncertainties, perhaps driven by intrinsic variation in the M K S -M * relation or underestimated uncertainties in the input parallaxes. We find that the effect of [Fe/H] on the M K S -M * relation is likely negligible for metallicities in the solar neighborhood (0.0±2.2% change in mass per dex change in [Fe/H]). This weak effect is consistent with predictions from the Dartmouth Stellar Evolution Database, but inconsistent with those from MESA Isochrones and Stellar Tracks (at 5σ). A sample of binaries with a wider range of abundances will be required to discern the importance of metallicity in extreme populations (e.g., in the Galactic halo or thick disk).

Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 R ⊕

“…We used these relationships to compute radii and masses of our M dwarfs. We added the model uncertainties from Mann et al (2015) and Mann et al (2019) in quadrature to our calculated Monte Carlo uncertainties, yielding average radius and mass uncertainties of 3.1% and 6.6%, respectively. From mass and radius, we calculated surface gravity for these stars using log g = log(GM ⋆ /R 2 ⋆ ).…”

Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra

“…Secondly, exoplanetary studies also rely on stellar parameter determinations not only to enable the determination of both planetary radii and masses (e.g. Mann et al 2019;Schweitzer et al 2019) but also to characterise the habitable zones around planet-harbouring stars (Kasting et al 1993;Kopparapu et al 2013). Furthermore, correlations between the stellar metallicity and planet occurrence rates are now well established and shed light on planet formation mechanisms (Adibekyan et al 2014;Montes et al 2018;Delgado Mena et al 2018).…”

Magnetic Inflation and Stellar Mass. V. Intensification and Saturation of M-dwarf Absorption Lines with Rossby Number

“…This resulted in 102 targets for the NIRSPEC sample. We then estimated their masses using the M Ks -to-mass relationship from Mann et al (2019).…”

“…Mass versus rotation period and Rossby Number for the objects in the full sample and those observed. Masses were calculated using the mass-luminosity relations ofMann et al (2019), rotation periods are from…”

“…We lack CARMENES data for the Ti I (5) line. The colorbar indicates the M dwarf mass, determined using mass-luminosity relationships fromMann et al (2019). The outliers in Ti I (4) and Ti I (6) appear to be due to contaminated CARMENES spectra and are marked with a red circle.…”