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Related papers: Calibrating M dwarf metallicities using molecular …

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Detailed chemical composition of stars is of prime interest for a range of topics in modern stellar astrophysics, such as the chemical evolution of the Galaxy or the formation, composition, and structure of exoplanets. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-01-18 C. Duque-Arribas , H. M. Tabernero , D. Montes , J. A. Caballero

We present here medium resolution (\lambda /\Delta\lambda\sim1200) H- and K-band spectra of M type dwarf stars covering the wavelength range 1.50 - 1.80 {\mu}m and 1.95 - 2.45 {\mu}m. The sample includes 53 dwarf stars (M0V-M7V) from new…

Solar and Stellar Astrophysics · Physics 2021-07-30 Dhrimadri Khata , Soumen Mondal , Ramkrishna Das , Supriyo Ghosh , Samrat Ghosh

Based on synthetic flux spectra calculated from theoretical atmospheric models, a calibration of temperature and metallicity for the dwarfs observed in the Beijing-Arizona-Taiwan-Connecticut (BATC) multicolor photometric system is presented…

Astrophysics · Physics 2009-11-10 Cui-hua Du , Xu Zhou , Jun Ma , Jian-rong Shi , Alfred Bing-Chih Chen , Zhao-ji Jiang , Jian-sheng

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

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…

The determination of the stellar parameters of M dwarfs is of prime importance in the fields of galactic, stellar and planetary astronomy. M stars are the least studied galactic component regarding their fundamental parameters. Yet, they…

Solar and Stellar Astrophysics · Physics 2015-05-27 V. Neves , X. Bonfils , N. C. Santos

Context. M subdwarfs are metal poor and cool stars. They are important probes of the old galactic populations. However, they remain elusive due to their low luminosity. Observational and modeling efforts are required to fully understand…

Solar and Stellar Astrophysics · Physics 2015-06-18 A. S. Rajpurohit , C. Reyle , F. Allard , R. -D. Scholz , D. Homeier , M. Schultheis , A. Bayo

Line depth ratios measured on high resolution (R=42000), high S/N echelle spectra are used for the determination of precise effective temperatures of 181 F,G,K Main Sequence stars with about solar metallicity (-0.5 < [Fe/H] < +0.5). A set…

Astrophysics · Physics 2009-11-10 V. V. Kovtyukh , C. Soubiran , S. I. Belik , N. I. Gorlova

We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE…

We present metallicity and photometric parallax calibrations for the F and G type dwarfs with photometric, astrometric and spectroscopic data. The sample consists of 168 dwarf stars covering the colour, iron abundance and absolute magnitude…

Astrophysics of Galaxies · Physics 2016-06-15 S. Tuncel Guctekin , S. Bilir , S. Karaali , S. Ak , T. Ak , Z. F. Bostanci

High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…

Astrophysics · Physics 2009-10-31 Y. Q. Chen , P. E. Nissen , G. Zhao , H. W. Zhang , T. Benoni

With the existing and upcoming large multi-fibre low-resolution spectrographs, the question arises how precise stellar parameters such as Teff and [Fe/H] can be obtained from low-resolution K-band spectra with respect to traditional…

Solar and Stellar Astrophysics · Physics 2016-05-04 M. Schultheis , N. Ryde , G. Nandakumar

We performed a uniform and detailed analysis of 1112 high-resolution spectra of FGK dwarfs obtained with the HARPS spectrograph at the ESO 3.6 m telescope (La Silla, Chile). Most stars have effective temperatures 4700 K < Teff < 6300 K and…

Astrophysics of Galaxies · Physics 2011-11-22 V. Zh. Adibekyan , N. C. Santos , S. G. Sousa , G. Israelian

We have developed a photometric abundance indicator for G and K dwarfs, based on accurate, spectroscopically determined abundances for G and K dwarfs of Morell, K\"allander and Butcher (1992) and Morell (1994). Broadband Cousins R-I…

Astrophysics · Physics 2015-06-24 Chris Flynn , Olof Morell

Precise and accurate parameters for late-type (late K and M) dwarf stars are important for characterization of any orbiting planets, but such determinations have been hampered by these stars' complex spectra and dissimilarity to the Sun. We…

Solar and Stellar Astrophysics · Physics 2015-06-03 Andrew W. Mann , Gregory A. Feiden , Eric Gaidos , Tabetha Boyajian , Kaspar von Braun

We present a catalog of uniformly determined stellar properties and abundances for 1626 F, G, and K stars using an automated spectral synthesis modeling procedure. All stars were observed using the HIRES spectrograph at Keck Observatory.…

Solar and Stellar Astrophysics · Physics 2016-08-24 John M. Brewer , Debra A. Fischer , Jeff A. Valenti , Nikolai Piskunov

We explored here the near-infrared $H$-band atmospheric window aiming to provide quantitative diagnostic tools for deriving stellar parameters, for instance, effective temperature ($T_{eff}$) and metallicity ([$Fe/H$]), of cool giants…

Solar and Stellar Astrophysics · Physics 2022-02-02 Supriyo Ghosh , J. P. Ninan , D. K. Ojha

Neutral Fe lines in metal-poor stars yield conflicting abundances depending on whether and how deviations from local thermodynamic equilibrium (LTE) are considered. We have collected new high resolution and high signal-to-noise ultraviolet…

Solar and Stellar Astrophysics · Physics 2018-07-04 Ian U. Roederer , Christopher Sneden , James E. Lawler , Jennifer S. Sobeck , John J. Cowan , Ann Merchant Boesgaard

88 dwarfs, covering the colour index interval 0.37 <(B-V)o <= 1.07 mag, with metallicities -2.70 <= [Fe/H] <= +0.26 dex have been taken from three different sources for new metallicity calibration. The catalogue of Cayrel de Stroble et al.…

Astrophysics · Physics 2009-11-07 S. Karaali , S. Bilir , Y. Karatas , S. G. Ak

We present empirical calibrations that estimate stellar metallicity, effective temperature and surface gravity as a function of Lick/IDS indices. These calibrations have been derived from a training set of 261 stars for which (1)…

Astrophysics · Physics 2016-08-30 Sarah E. Robinson , Jay Strader , S. Mark Ammons , Gregory Laughlin , Debra Fischer