English
Related papers

Related papers: Calibrating M dwarf metallicities using molecular …

200 papers

We report iron and titanium abundance measurements from high resolution spectra in a volume-limited sample of 106 M0 and M0.5 dwarf stars. The sample includes stars north of the celestial equator and closer than 29 parsecs. The results…

Solar and Stellar Astrophysics · Physics 2020-04-29 Vincent M. Woolf , George Wallerstein

The analysis of stellar spectra depends upon the effective temperature (Teff) and the surface gravity (log g). However, the estimation of log g with high accuracy is challenging. A classical approach is to search for log g that satisfies…

Solar and Stellar Astrophysics · Physics 2021-07-07 Noriyuki Matsunaga , Mingjie Jian , Daisuke Taniguchi , Scarlet Saez Elgueta

We present the results from high-resolution spectroscopic measurements to determine metallicities and activities of bright stars in the southern hemisphere. We have measured the iron abundances ([Fe/H]) and chromospheric emission indices…

Astrophysics · Physics 2009-11-13 J. S. Jenkins , H. R. A. Jones , Y. Pavlenko , D. J. Pinfield , J. R. Barnes , Y. Lyubchik

Based on the near infrared spectra of 42 M dwarfs, carbon abundances are determined from the ro-vibrational lines of CO 2-0 band. We use Teff values based on the angular diameters if available or apply a logTeff - M3.4 (the absolute…

Solar and Stellar Astrophysics · Physics 2015-06-22 Takashi Tsuji , Tadashi Nakajima

The consistency of the metallicity distributions of F, G and K dwarfs is studied. We present a new metallicity distribution for K dwarfs using metallicities determined from uvby photometry. There is a remarkable paucity of metal-poor K…

Astrophysics · Physics 2007-05-23 H. J. Rocha-Pinto , W. J. Maciel

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.,…

We present a series of systematic abundance measurements for 89 hot DA white dwarfs drawn from the FUSE observation archive. These stars span the temperature range ~ 20000-70000K, and form the largest sample to-date, exceeding our earlier…

Solar and Stellar Astrophysics · Physics 2013-02-27 M. A. Barstow , S. L. Casewell , J. B. Holberg , J. K. Barstow

One of the most important factors in determining the stellar lithium abundance is the effective temperature. In a previous study by the authors, new effective temperatures Teff for sixteen metal-poor halo dwarfs were derived using a local…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. Hosford , A. E. Garcia Perez , R. Collet , S. G. Ryan , J. E. Norris , K. A. Olive

Chlorine abundances are reported in 15 evolved giants and one M dwarf in the solar neighborhood. The Cl abundance was measured using the vibration-rotation 1-0 P8 line of H$^{35}$Cl at 3.69851 $\mu$m. The high resolution L-band spectra were…

Solar and Stellar Astrophysics · Physics 2016-12-05 Z. G. Maas , C. A. Pilachowski , K. Hinkle

The ability to measure metallicities and {\alpha}-element abundances in individual red giant branch (RGB) stars using medium-resolution spectra ($R \approx 6000$) is a valuable tool for deciphering the nature of Milky Way dwarf satellites…

Astrophysics of Galaxies · Physics 2015-06-15 Lei Yang , Evan N. Kirby , Puragra Guhathakurta , Eric W. Peng , Lucy Cheng

Knowledge of the metallicities of M dwarfs rests predominantly on the photometric calibration of Bonfils and collaborators, which predicts that M dwarfs in the solar neighborhood, including those with known planets, are systematically…

Earth and Planetary Astrophysics · Physics 2011-02-11 John A. Johnson , Kevin Apps

We present up-to-date metallicity-dependent temperature vs. color calibrations for main sequence and giant stars based on temperatures derived with the infrared flux method (IRFM). Seventeen colors in the following photometric systems: UBV,…

Astrophysics · Physics 2010-04-06 Ivan Ramirez , Jorge Melendez

We present a detailed chemical abundance analysis of the eclipsing binary system V505 Per. High resolution spectra were analyzed using the MOOG spectrum analysis code, and we determined abundances not only for iron and lithium but also for…

Solar and Stellar Astrophysics · Physics 2026-05-13 Zohreh Safari Forushani , Catherine A. Pilachowski , Gloria Koenigsberger , Derek Sikorski , Maria Cordero

We have performed a differential, line-by-line, chemical abundance analysis, ultimately relative to the Sun, of nine very metal-poor main sequence halo stars, near [Fe/H]=$-$2 dex. Our abundances range from…

Solar and Stellar Astrophysics · Physics 2017-04-05 Erin O'Malley , Andrew McWilliam , Brian Chaboyer , Ian Thompson

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

We present spectroscopic determinations of the effective temperatures, surface gravities and metallicities for 21 M-dwarfs observed at high-resolution (R $\sim$ 22,500) in the \textit{H}-band as part of the SDSS-IV APOGEE survey. The…

Empirical correlations between stellar parameters such as rotation or radius and magnetic activity diagnostics require estimates of the effective temperatures and the stellar radii. The aim of this study is to propose simple methods that…

Solar and Stellar Astrophysics · Physics 2019-07-17 Eric R. Houdebine , D. J. Mullan , J. G. Doyle , Geoffroy de La Vieuville , C. J. Butler , F. Paletou

How can we accurately determine the metallicity of faint red giant stars in nearby galaxies? The equivalent widths of the broad absorption lines from Ca II at 8498, 8542, and 8662 Angstrom (the calcium triplet) have shown a smooth…

Astrophysics · Physics 2007-05-23 T. Bosler , T. Smecker-Hane , A. McWilliam

Using the stellar atmospheric parameters such as effective temperature and metallicity derived from SDSS spectra for 2200 main sequence (MS) stars which were also observed by Beijing - Arizona - Taiwan - Connecticut (BATC) photometric…

Astrophysics of Galaxies · Physics 2015-06-16 Xiyan Peng , Cuihua Du , Zhenyu Wu , Jun Ma , Xu Zhou

We investigate the stellar metallicity ([Fe/H] and [M/H]) dependence of giant planets around M dwarfs by comparing the metallicity distribution of 746 field M dwarfs without known giant planets with a sample of 22 M dwarfs hosting confirmed…

Earth and Planetary Astrophysics · Physics 2024-12-12 Tianjun Gan , Christopher A. Theissen , Sharon X. Wang , Adam J. Burgasser , Shude Mao