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Related papers: Investigating the possible connection between lamb…

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Context: Hot subdwarf B stars (sdBs) are considered to be core helium-burning stars with very thin hydrogen envelopes situated on or near the extreme horizontal branch (EHB). The formation of sdBs is still unclear as well as the chemical…

Solar and Stellar Astrophysics · Physics 2015-06-12 S. Geier

The characteristics of the stellar populations in the Galactic Bulge inform and constrain the Milky Way's formation and evolution. The metal-poor population is particularly important in light of cosmological simulations, which predict that…

We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis…

Solar and Stellar Astrophysics · Physics 2016-12-07 Julia E. O'Connell , Kylee Martens , Peter M. Frinchaboy

Recent LTE analyses (Israelian et al. 1998 and Bosegaard et al. 1999) of the OH bands in the optical-ultraviolet spectra of nearby metal-poor subdwarfs indicate that oxygen abundances are generally higher than those previously determined.…

Astrophysics · Physics 2009-10-31 Jon P. Fulbright , Robert P. Kraft

As an investigation of the origin of ``$\alpha$-poor'' halo stars, we analyze kinematic and abundance data for 73 intermediate metallicity stars ($-1 >$ [Fe/H] $\geq -2$) selected from Paper I of this series. We find evidence for a…

Astrophysics · Physics 2009-12-08 Jon P. Fulbright

We report the results of abundance determination for the components of the SB2 star 66 Eri (M_A/M_B=0.97) from high resolution CCD echelle spectra with S/N>=100 taken with the 1-m telescope of Special Astrophysical Observatory (Zelenchuck,…

Astrophysics · Physics 2007-05-23 A. V. Yushchenko , V. F. Gopka , V. L. Khokhlova , F. A. Musaev , I. F. Bikmaev

We present the average abundances of the intermediate elements obtained by performing a stacked analysis of all the galaxy clusters in the archive of the X-ray telescope ASCA. We determine the abundances of Fe, Si, S, and Ni as a function…

Astrophysics · Physics 2009-11-10 W. H. Baumgartner , M. Loewenstein , D. J. Horner , R. F. Mushotzky

High-resolution spectra of lambda Bootis stars reveal the presence of circumstellar gas for example in the Ca K line. The example of the normal A star beta Pictoris shows, that the narrow stable absorption component in Ca K can be…

Astrophysics · Physics 2007-05-23 I. Kamp , H. Holweger

We have obtained new detailed abundances of the Fe-group elements Sc through Zn (Z=21-30) in three very metal-poor ([Fe/H] $\approx -3$) stars: BD 03 740, BD -13 3442 and CD -33 1173. High-resolution ultraviolet HST/STIS spectra in the…

The results of the abundance analyses of six lambda Bootis stars are presented. For three stars, the impact of individual ODFs and various treatments of convection in the calculactions of the model atmospheres are investigated.

Astrophysics · Physics 2007-05-23 U. Heiter

We present CN and CH indices and CaII triplet metallicities for 34 giant stars and chemical abundances for 33 elements in 14 giants in the globular cluster M2. Assuming the program stars are cluster members, our analysis reveals (i) an…

As part of a large investigation with Hubble Space Telescope to study the faintest stars within the globular cluster Omega Centauri, in this work we present early results on the multiplicity of its main sequence (MS) stars, based on deep…

Solar and Stellar Astrophysics · Physics 2017-05-31 A. P. Milone , A. F. Marino , L. R. Bedin , J. Anderson , D. Apai , A. Bellini , P. Bergeron , A. J. Burgasser , A. Dotter , J. M. Rees

We present an elemental abundance analysis for four newly discovered ultra metal-poor stars from the Hamburg/ESO survey, with $\mathrm{[Fe/H]}\leq-4$. Based on high-resolution, high signal-to-noise spectra, we derive abundances for 17…

We investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…

We present high-resolution spectroscopic observations of the \ion{Li}{1} resonance line in a sample of 62 stars that belong to 31 common-proper motion pairs with twin F or G-type components. Photospheric abundances of lithium were derived…

Astrophysics · Physics 2009-11-07 Eduardo L. Martin , Gibor Basri , Yakiv Pavlenko , Yuri Lyubchik

We report on the observations of two ultra metal-poor (UMP) stars with [Fe/H]~-4.0 including one new discovery. The two stars are studied in the on-going and quite efficient project to search for extremely metal-poor (EMP) stars with LAMOST…

Solar and Stellar Astrophysics · Physics 2015-08-06 Haining Li , Wako Aoki , Gang Zhao , Satoshi Honda , Norbert Christlieb , Takuma Suda

Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the…

Using the 2dF multi-fibre instrument on the AAT, moderate resolution spectra have been obtained for a large sample of stars on the main sequence and at the turnoff in the unusual globular cluster omega Centauri. We investigate the behaviour…

Astrophysics · Physics 2009-11-11 G. S. Da Costa , Laura Stanford , John E. Norris , R. D. Cannon

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

Astrophysics of Galaxies · Physics 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

We determined the chemical composition of a large sample of weak G band stars -- a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J.…

Solar and Stellar Astrophysics · Physics 2013-03-04 Jens Adamczak , David L. Lambert