Spectro-Thermometry of M Dwarfs and Their Candidate Planets: Too Hot, Too Cool, or Just Right?

Mann, Andrew W.; Gaidos, Eric; Ansdell, Megan

doi:10.1088/0004-637x/779/2/188

Cited by 209 publications

(414 citation statements)

References 110 publications

Supporting

Mentioning

387

Contrasting

Order By: Relevance

“…This relation was created by fitting to the 8 pc stellar sample of Reid & Gizis (1997). Although most of the stars in this sample are inactive, and active stars may have higher bolometric luminosities, our derived values are ∼35% lower than those found for the inactive early-type dwarfs in Mann et al (2013) and agree well with the values of Dieterich et al (2014) for late-type dwarfs. We next calculated the Hα luminosity of the DR7 and PMSU samples following West et al (2011), which integrates over a line region of width 8 Å, and subtracts the nearby continuum (see Table 1 and Section 2.2 in West et al 2011).…”

Section: Discussionsupporting

confidence: 69%

A Catalog of Galex Ultraviolet Emission From Spectroscopically Confirmed M Dwarfs*

Jones¹,

West²

2016

ApJ

View full text Add to dashboard Cite

We present a catalog of Galaxy Evolution Explorer Near-UV (NUV) and Far-UV (FUV) photometry for the Palomar/MSU and SDSS DR7 spectroscopic M dwarf catalogs. The catalog contains NUV measurements matched to 577 spectroscopically confirmed M dwarfs and FUV measurements matched to 150 spectroscopically confirmed M dwarfs. Using these data, we find that NUV and FUV luminosities strongly correlate with Hα emission, a typical indicator of magnetic activity in M dwarfs. We also examine the fraction of M dwarfs with varying degrees of strong line emission at NUV wavelengths. Our results indicate that the frequency of M dwarf NUV emission peaks at intermediate spectral types, with at least ∼30% of young M4-M5 dwarfs having some level of activity. For mid-type M dwarfs, we show that NUV emission decreases with distance from the Galactic plane, a proxy for stellar age. Our complete matched source catalog is available online.

show abstract

Section: Discussionsupporting

confidence: 69%

A Catalog of Galex Ultraviolet Emission From Spectroscopically Confirmed M Dwarfs*

Jones¹,

West²

2016

ApJ

View full text Add to dashboard Cite

show abstract

“…SNIFS provides spectra covering 3200-9700 Å at a resolution of l l D = 700-1000. Full details on data reduction can be found in Aldering et al (2002) and Mann et al (2013b). The resulting spectrophotometric calibration of SNIFS spectra has been shown to be good to 2%-3% (Mann et al 2013b), which is sufficient to establish fundamental stellar parameters of M dwarfs.…”

Section: Optical Low-resolution Spectroscopymentioning

confidence: 93%

“…We derived the effective temperature following the procedure from Mann et al (2013b). To briefly summarize, we compare our optical spectrum to BT-SETTL models (Allard et al 2013) calibrated to reproduce the temperatures of nearby stars with radii and temperatures measured from long-baseline interferometry (Boyajian et al 2012).…”

Section: Optical Low-resolution Spectroscopymentioning

confidence: 99%

THEK2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF

Hirano

Fukui

Mann

et al. 2016

ApJ

Self Cite

View full text Add to dashboard Cite

We validate a R R 2.32 0.24 p =  Å planet on a close-in orbit (P=2.260455±0.000041 days) around K2-28 (EPIC206318379), a metal-rich M4-type dwarf in the Campaign 3 field of the K2 mission. Our follow-up observations included multi-band transit observations from the optical to the near-infrared, low-resolution spectroscopy, and high-resolution adaptive optics (AO) imaging. We perform a global fit to all of the observed transits using a Gaussian process-based method and show that the transit depths in all of the passbands adopted for the ground-based transit follow-ups (r z J H K , , , ,¢ ) are within ∼2σ of the K2 value. Based on a model of the background stellar population and the absence of nearby sources in our AO imaging, we estimate the probability that a background eclipsing binary could cause a false positive to be <2×10 −5 . We also show that K2-28 cannot have a physically associated companion of stellar type later than M4, based on the measurement of almost identical transit depths in multiple passbands. There is a low probability for an M4 dwarf companion ( 0.072 0.04 0.02 » -+), but even if this were the case, the size of K2-28b falls within the planetary regime. K2-28b has the same radius (within 1σ) and experiences irradiation from its host star similar to the well-studied GJ1214b. Given the relative brightness of K2-28 in the near-infrared (m 14.85 Kep = mag and m H =11.03 mag) and relatively deep transit (0.6%-0.7%), a comparison between the atmospheric properties of these two planets with future observations would be especially interesting.

show abstract

“…BO12 list 22 low-mass stars with spectral-types equal to or cooler than K5V, spanning a range of T eff between 3000 Mann et al (2013b) and spectral types from BO12. For GJ176 and GJ876, T eff values are adopted from Newton et al (2015) and spectral types from the GJ catalogue (Gliese & Jahreiß 1991). and 4500 K. HARPS spectra were obtained for seven stars from the ESO archive, whilst HARPS-N spectra were obtained for three stars from the TNG archive.…”

Section: Effective Temperaturementioning

confidence: 99%

Stellar parameters of early-M dwarfs from ratios of spectral features at optical wavelengths

Maldonado

Affer

Micela

et al. 2015

A&A

View full text Add to dashboard Cite

Context. Low-mass stars have been recognised as promising targets in the search for rocky, small planets with the potential of supporting life. As a consequence, Doppler search programmes using high-resolution spectrographs like HARPS or HARPS-N are providing huge quantities of optical spectra of M dwarfs. However, determining the stellar parameters of M dwarfs using optical spectra has proven to be challenging. Aims. We aim to calibrate empirical relationships to determine accurate stellar parameters for early-M dwarfs (spectral types M0-M4.5) using the same spectra as those that are used for radial velocity determinations, without the necessity of acquiring IR spectra or relying on atmospheric models and/or photometric calibrations. Methods. Our methodology consists of using ratios of pseudo-equivalent widths of spectral features as a temperature diagnostic, a technique frequently used in solar-type stars. Stars with effective temperatures obtained from interferometric estimates of their radii are used as calibrators. Empirical calibrations for the spectral type are also provided. Combinations of features and ratios of features are used to derive calibrations for the stellar metallicity. Our methods are then applied to a large sample of M dwarfs that are currently being observed in the framework of the HARPS GTO search for extrasolar planets. The derived temperatures and metallicities are used together with photometric estimates of mass, radius, and surface gravity to calibrate empirical relationships for these parameters. Results. A long list of spectral features in the optical spectra of early-M dwarfs was identified. This list shows that the pseudoequivalent width of roughly 43% of the features is strongly anticorrelated with the effective temperature. The correlation with the stellar metallicity is weaker. A total of 112 temperature sensitive ratios were identified and calibrated over the range 3100−3950 K, providing effective temperatures with typical uncertainties of about 70 K. Eighty-two ratios of pseudo-equivalent widths of features were calibrated to derive spectral types within 0.5 subtypes for stars with spectral types between K7V and M4.5V. We calibrated 696 combinations of the pseudo-equivalent widths of individual features and temperature-sensitive ratios for the stellar metallicity over a metallicity range from −0.54 to +0.24 dex, with estimated uncertainties in the range of 0.07−0.10 dex. We provide our own empirical calibrations for stellar mass, radius, and surface gravity. These parameters depend on the stellar metallicity. For a given effective temperature, lower metallicities predict lower masses and radii as well as higher gravities.

show abstract

Spectro-Thermometry of M Dwarfs and Their Candidate Planets: Too Hot, Too Cool, or Just Right?

Cited by 209 publications

References 110 publications

A Catalog of Galex Ultraviolet Emission From Spectroscopically Confirmed M Dwarfs*

A Catalog of Galex Ultraviolet Emission From Spectroscopically Confirmed M Dwarfs*

THEK2-ESPRINT PROJECT III: A CLOSE-IN SUPER-EARTH AROUND A METAL-RICH MID-M DWARF

Stellar parameters of early-M dwarfs from ratios of spectral features at optical wavelengths

Contact Info

Product

Resources

About