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Related papers: A search for cool subdwarfs: Stellar parameters fo…

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We present an update of our low-resolution spectroscopic follow-up and model atmosphere analysis of hot subdwarf stars from the Galaxy Evolution Explorer (GALEX) survey. Targets were selected on the basis of colour indices calculated from…

Solar and Stellar Astrophysics · Physics 2012-12-06 Péter Németh , Adéla Kawka , Stéphane Vennes

We present a self-consistent study of cool supergiants (CSGs) belonging to the Magellanic clouds. We calculated stellar atmospheric parameters using LTE KURUCZ and MARCS atmospheric models for more than 400 individual targets by fitting a…

Solar and Stellar Astrophysics · Physics 2018-02-28 H. M. Tabernero , R. Dorda , I. Negueruela , C. Gonzalez-Fernandez

We present a value-added catalog containing stellar parameters estimated from 7.10 million low-resolution spectra for 5.16 million unique stars with spectral signal-to-noise ratios (SNRs) higher than 10 obtained by the Large Sky Area…

Solar and Stellar Astrophysics · Physics 2022-04-06 Chun Wang , Yang Huang , Haibo Yuan , Huawei Zhang , Maosheng Xiang , Xiaowei Liu

Context: Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims: We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82…

We report progress in the calibration of a method to determine cool dwarf star metallicities using molecular band strength indices. The molecular band index to metallicity relation can be calibrated using chemical abundances calculated from…

Astrophysics · Physics 2009-11-13 Vincent M Woolf , George Wallerstein

We report the discovery of LEHPM 2-59 as the coolest extreme M subdwarf (esdM) found to date. Optical and near infrared spectroscopy demonstrate that this source is of later spectral type than the esdM7 APMPM 0559-2903, with the presence of…

Astrophysics · Physics 2009-11-11 Adam J. Burgasser , J. Davy Kirkpatrick

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…

Detailed chemical studies of F/G/K -- or Solar-type -- stars have long been routine in stellar astrophysics, enabling studies in both Galactic chemodynamics, and exoplanet demographics. However, similar understanding of the chemistry of M…

In this work, we identify 734 ultracool dwarfs with a spectral type of M6 or later, including one L0. Of this sample, 625 were studied spectroscopically for the first time. All of these ultracool dwarfs are within 360~pc, with a…

Solar and Stellar Astrophysics · Physics 2022-04-20 You-Fen Wang , A-Li Luo , Wen-Ping Chen , Hugh R. A. Jones , Bing Du , Yin-Bi Li , Shuo Zhang , Zhong-Rui Bai , Xiao Kong , Yan-Xin Guo

Benchmark stars are crucial as validating standards for current as well as future large stellar surveys of the Milky Way. However, the number of suitable metal-poor benchmarks is currently limited. We aim to construct a new set of…

Solar and Stellar Astrophysics · Physics 2020-08-05 I. Karovicova , T. R. White , T. Nordlander , L. Casagrande , M. Ireland , D. Huber , P. Jofré

We present the discovery of twelve metal-poor and distant pre-main sequence (PMS) candidates in the dwarf irregular galaxy Wolf-Lundmark-Melotte (WLM)~968 kpc away, at a present-day metallicity of [Fe/H] around $-$0.9. These candidates have…

Solar and Stellar Astrophysics · Physics 2025-01-30 Venu M. Kalari , Ricardo Salinas , Morten Andersen , Guido De Marchi , Monica Rubio , Jorick S. Vink , Hans Zinnecker

We report the discovery of two new ZZ Ceti pulsators, LP 133-144 and HE 1258+0123, selected on the basis of model atmosphere fits to optical spectroscopic data. The atmospheric parameters for LP 133-144, Teff = 11,800 +/- 200 K and log g =…

Astrophysics · Physics 2009-11-10 P. Bergeron , G. Fontaine , M. Billeres , S. Boudreault , E. M. Green

The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Characterising our…

We present optical spectroscopy and near-infrared photometry of 57 faint ($g= 19-22$) high proper motion white dwarfs identified through repeat imaging of $\approx3100$ square degrees of the Sloan Digital Sky Survey footprint by Munn et al.…

Solar and Stellar Astrophysics · Physics 2016-09-07 Kyra Dame , A. Gianninas , Mukremin Kilic , Jeffrey A. Munn , Warren R. Brown , Kurtis A. Williams , Ted von Hippel , Hugh C. Harris

Context: The full spectrum fitting of stellar spectra against a library of empirical spectra is a well-established approach to measure the atmospheric parameters of FGK stars with a high internal consistency. Extending it towards cooler…

Solar and Stellar Astrophysics · Physics 2015-12-17 Kaushal Sharma , Philippe Prugniel , Harinder P. Singh

The determination of effective temperatures of very hot central stars (Teff>70000K) by model atmosphere analyses of optical H and He line profiles is afflicted with considerable uncertainty, primarily due to the lack of neutral helium…

Astrophysics · Physics 2007-05-23 K. Werner , J. L. Deetjen , S. Dreizler , T. Rauch , J. W. Kruk

Ultracool dwarf stars and brown dwarfs provide a unique probe of large-scale Galactic structure and evolution; however, until recently spectroscopic samples of sufficient size, depth, and fidelity have been unavailable. Here, we present the…

We present the first results of a survey of blue horizontal branch (BHB) stars in the Galactic bulge. 164 candidates with 15 < V < 17.5 in a field 7.5deg from the Galactic Center were observed in the blue at 2.4A FWHM resolution with the…

Astrophysics · Physics 2009-10-31 Ruth C. Peterson , Donald M. Terndrup , Elaine M. Sadler , Alistair R. Walker

We present new grids of colors and bolometric corrections for F-K stars having 4000 K < Teff < 6500 K, 0.0 < log g < 4.5 and -3.0 < [Fe/H] < 0.0. A companion paper extends these calculations into the M giant regime. Colors are tabulated for…

Astrophysics · Physics 2009-10-12 Mark L. Houdashelt , Roger A. Bell , Allen V. Sweigart

We present a new direct spectroscopic calibration for a fast estimation of the stellar metallicity [Fe/H]. These calibrations were computed using a large sample of 451 solar-type stars for which we have precise spectroscopic parameters…

Solar and Stellar Astrophysics · Physics 2012-09-04 Sérgio G. Sousa , Nuno C. Santos , Garik Israelian