English
Related papers

Related papers: The M dwarf problem: Fe and Ti abundances in a vol…

200 papers

We present high-resolution spectroscopic measurements of the abundances of titanium (Ti), yttrium (Y) and lanthanum (La) for M giant candidates of the Sagittarius (Sgr) dwarf spheroidal (dSph) + tidal tail system pre-selected on the basis…

We present the first spectroscopic metallicities of three M dwarfs with known or candidate planetary mass companions. We have analyzed high resolution, high signal-to-noise spectra of these stars which we obtained at McDonald Observatory.…

Astrophysics · Physics 2009-11-11 Jacob L. Bean , G. Fritz Benedict , Michael Endl

We present interferometric diameter measurements of 21 K- and M- dwarfs made with the CHARA Array. This sample is enhanced by literature radii measurements to form a data set of 33 K-M dwarfs with diameters measured to better than 5%. For…

We present a survey of lithium abundances in 185 main- sequence field stars with Teff between 5600 and 6600 K and [Fe/H] from -1.4 to +0.2 based on high-resolution spectra of 130 stars and a reanalysis of data from Lambert et al. (1991).…

Astrophysics · Physics 2009-11-06 Y. Q. Chen , P. E. Nissen , T. Benoni , G. Zhao

We empirically determine effective temperatures and bolometric luminosities for a large sample of nearby M dwarfs, for which high accuracy optical and infrared photometry is available. We introduce a new technique which exploits the flux…

Astrophysics · Physics 2009-11-13 L. Casagrande , C. Flynn , M. Bessell

The bulk-metallicity determination of giant exoplanets is essential to constrain their formation and evolution pathways and to compare them to the solar system. Previous studies inferred an inverse relation between the mass and bulk…

Earth and Planetary Astrophysics · Physics 2024-12-25 Simon Müller , Ravit Helled

Oxygen abundances are derived in a sample of 13 field F and G dwarfs and subgiants with metallicities in the range of -0.75 < [Fe/H] < +0.15. This is the same sample of stars for which boron abundances have been derived earlier from…

Astrophysics · Physics 2009-11-06 Verne V. Smith , Katia Cunha , Jeremy R. King

The most abundant stars in the Galaxy, M dwarfs, are very commonly hosts to diverse systems of low-mass planets. Their abundancy implies that the general occurrence rate of planets is dominated by their occurrence rate around such M dwarfs.…

A previous study (Nissen & Schuster 2010) of 94 dwarf stars with -1.6 < [Fe/H] < -0.4 has revealed the existence of two distinct halo populations with a systematic difference in [alpha/Fe] at a given metallicity. In continuation of that…

Astrophysics of Galaxies · Physics 2015-05-27 Poul E. Nissen , William J. Schuster

We have performed the detailed analysis of 174 high-resolution spectra of FGK dwarfs obtained with the ELODIE echelle spectrograph at the Observatoire de Haute-Provence. Abundances of Fe, Si and Ni have been determined from equivalent…

Astrophysics · Physics 2009-11-10 T. V. Mishenina , C. Soubiran , V. V. Kovtyukh , S. A. Korotin

In this work, we present new catalogs of M giant and M dwarf stars from the LAMOST DR5. In total, 39,796 M giants and 501,152 M dwarfs are identified from the classification pipeline. The template-fitting results contain M giants with 7…

Astrophysics of Galaxies · Physics 2019-09-25 Jing Zhong , Jing Li , Jeffrey L. Carlin , Li Chen , Rene A. Mendez , Jinliang Hou

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai…

We present NIR synthetic spectra based on PHOENIX stellar atmosphere models of typical early and mid M dwarfs with varied C and O abundances. We apply multiple recently published methods for determining M dwarf metallicity to our models to…

Solar and Stellar Astrophysics · Physics 2016-09-21 Mark J. Veyette , Philip S. Muirhead , Andrew W. Mann , France Allard

We present an all-sky catalog of M dwarf stars with apparent infrared magnitude J<10. The 8,889 stars are selected from the ongoing SUPERBLINK survey of stars with proper motion >40 mas/yr, supplemented on the bright end with the TYCHO-2…

Solar and Stellar Astrophysics · Physics 2015-05-30 Sébastien Lépine , Eric Gaidos

Following our solar work, we perform NLTE calculations of the Mn abundance for fourteen stars with [Fe/H] from 0 to -2.5, mainly to show how NLTE affects Mn abundances in cool stars of different metallicities.The spectrum synthesis and Mn…

Astrophysics · Physics 2009-11-13 Maria Bergemann , Thomas Gehren

We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 ``single'' stars. The results show that the [X/H] abundances (with X = Na, Mg and Al) are, on average, higher in stars with…

Astrophysics · Physics 2009-11-10 P. Beirao , N. C. Santos , G. Israelian , M. Mayor

An extensive study on the potassium abundances of late-type stars was carried out by applying the non-LTE spectrum-fitting analysis to the K I resonance line at 7698.96A to a large sample of 160 FGK dwarfs and 328 late-G /early-K giants…

Solar and Stellar Astrophysics · Physics 2020-01-15 Yoichi Takeda

Low mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their…

Astrophysics of Galaxies · Physics 2016-03-09 P. François , L. Monaco , P. Bonifacio , C. Moni Bidin , D. Geisler , L. Sbordone

We present a differential abundance analysis of Hyades F-K dwarfs in search for evidence of stellar enrichment from accreted hydrogen deficient disk material. Metallicites and relative abundance ratios of several species have been…

Astrophysics · Physics 2008-11-26 Diane B. Paulson , Christopher Sneden , William D. Cochran

For the first time, we present an extensive study of stars with individual non-local thermodynamic equilibrium (NLTE) abundances for 17 chemical elements from Li to Eu in a sample of stars uniformly distributed over the $-2.62 \le$ [Fe/H]…