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Related papers: Metallicities in M dwarfs: Investigating different…

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We present a brief overview of a splinter session on determining the metallicity of low-mass dwarfs that was organized as part of the Cool Stars 16 conference. We review contemporary spectroscopic and photometric techniques for estimating…

Magnetic fields in cool stars can be investigated by measuring Zeeman line broadening and polarization in atomic and molecular lines. Similar to the Sun, these fields are complex and height-dependent. Many molecular lines dominating M-dwarf…

Solar and Stellar Astrophysics · Physics 2019-09-11 N. Afram , S. V. Berdyugina

In a series of three papers, we investigate the current status of published metallicities for open clusters that were derived from a variety of photometric and spectroscopic methods. The current article focuses on spectroscopic methods. The…

Astrophysics of Galaxies · Physics 2014-01-10 U. Heiter , C. Soubiran , M. Netopil , E. Paunzen

While the planet-metallicity correlation for FGK main-sequence stars hosting giant planets is well established, the results are not so clear for M-dwarf stars, for which precise metallicity measurements are not straightforward. However, new…

Solar and Stellar Astrophysics · Physics 2017-11-15 M. J. Hobson , E. Jofré , L. García , R. Petrucci , M. Gómez

Based on high resolution and high signal-to-noise ratio (S/N) spectra analysis of 90 solar type stars, we have established several new metallicity calibrations in Teff range [5600, 6500] K based on red spectra with the wavelength range of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 J. K. Zhao , G. Zhao , Y. Q. Chen , A. L. Luo

[Abridged] Several large scale photometric and spectroscopic surveys are being undertaken to provide a more detailed picture of the Milky Way. Given the necessity of generalisation in the determination of, e.g., stellar parameters when tens…

Astrophysics of Galaxies · Physics 2010-08-24 Anna S Arnadottir , Sofia Feltzing , Ingemar Lundstrom

From an initial sample of a few hundred stars selected for an Hipparcos program, a subsample of 33 objects with direct determination of their effective temperature, bolometric magnitude and [Fe/H] has been derived. An accurate observational…

Astrophysics · Physics 2007-05-23 Y. Lebreton , M. -N. Perrin , R. Cayrel , A. Baglin , J. Fernandes

We use the most homogeneous $Geneva$ seven-colour photometric system to derive new metallicity calibrations for early A- to K-type stars that cover both, dwarf stars and giants. The calibrations are based on several spectroscopic data sets…

Solar and Stellar Astrophysics · Physics 2017-06-21 Martin Netopil

Temperature, surface gravity, and metallicitity are basic stellar atmospheric parameters necessary to characterize a star. We aim to improve the description of the spectroscopic temperatures especially for the cooler stars where the…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. Tsantaki , S. G. Sousa , V. Zh. Adibekyan , N. C. Santos , A. Mortier , G. Israelian

The location of M dwarfs in the V-K_s--M_Ks color-magnitude diagram (CMD) has been shown to correlate with metallicity. We demonstrate that previous empirical photometric calibrations of M dwarf metallicity exploiting this correlation…

Earth and Planetary Astrophysics · Physics 2015-05-19 Kevin C. Schlaufman , Gregory Laughlin

The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of $\sim280,000$ stars with $-3.75 \lesssim$…

Astrophysics of Galaxies · Physics 2021-06-09 Anirudh Chiti , Anna Frebel , Mohammad K. Mardini , Tatsuya W. Daniel , Xiaowei Ou , Anastasiia V. Uvarova

We present metallicities derived from a sample of eleven M dwarfs belonging to wide binary systems with warmer FG primary companions observed by the high-resolution (R=22,500) near-infrared SDSS-IV APOGEE spectra. Using a plane-parallel…

Solar and Stellar Astrophysics · Physics 2025-03-17 Anderson da Silva-Andrade , Diogo Souto

The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27-day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are amongst the lowest…

In this study, abundances of the neutron-capture elements Rb, Sr, and Zr are derived, for the first time, in a sample of nearby M dwarfs. We focus on stars in the metallicity range -0.5<[Fe/H]<+0.3, an interval poorly explored for Rb…

The relevance of M dwarfs in the search for potentially habitable Earth-sized planets has grown significantly in the last years. In our on-going effort to comprehensively and accurately characterise confirmed and potential planet-hosting M…

We present a comparison of the predictions of stellar models with the luminosity of the lower main sequence ($5.5 < M_V < 7.3$) using K dwarfs in the Hipparcos catalog. The parallaxes of our comparison stars are known to better than 15% and…

Astrophysics · Physics 2009-11-07 Eira Kotoneva , Chris Flynn , Raul Jimenez

Context. Comparison studies of Sun-like stars with the Sun suggest an anomalously low photometric variability of the Sun compared to Sun-like stars with similar magnetic activity. Comprehensive understanding of stellar variability is…

Solar and Stellar Astrophysics · Physics 2018-11-21 V. Witzke , A. I. Shapiro , S. K. Solanki , N. A. Krivova , W. Schmutz

We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess, $\delta_{0.41}$ defined with $ugr$ data in the SDSS. We estimated the $M_g$ absolute…

Astrophysics of Galaxies · Physics 2017-09-04 S. Tuncel Guctekin , S. Bilir , S. Karaali , O. Plevne , S. Ak , T. Ak , Z. F. Bostanci

Around 16% of the solar-like stars in our neighbourhood show IR-excesses due to debris discs and a fraction of them are known to host planets. We aim to determine in a homogeneous way the metallicity of a sample of stars with known debris…

Earth and Planetary Astrophysics · Physics 2015-06-04 J. Maldonado , C. Eiroa , E. Villaver , B. Montesinos , A. Mora