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Related papers: The abundance pattern of the lambda Bootis stars

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We present results from the B-type Binaries Characterisation (BBC) programme, a multi-epoch spectroscopic study of 88 early B-type binary candidates in the 30 Doradus region of the Large Magellanic Cloud (LMC). From radial-velocity analysis…

Solar and Stellar Astrophysics · Physics 2021-08-11 J. I. Villaseñor , W. D. Taylor , C. J. Evans , O. H. Ramírez-Agudelo , H. Sana , L. A. Almeida , S. E. de Mink , P. L. Dufton , N. Langer

Abundance patterns of the elements C, N, and O are sensitive probes of stellar nucleosynthesis processes and, in addition, O abundances are an important input for stellar age determinations. Understanding the nature of the observed…

Astrophysics · Physics 2015-06-24 M. M. Briley , R. A. Bell , J. E. Hesser , G. H. Smith

A long sought after goal using chemical abundance patterns derived from metal-poor stars is to understand the Galactic chemical evolution (GCE) and to pin down the nature of the first stars (Pop III). Here, we use a sample of 14 metal-poor…

Elemental abundance patterns can provide vital clues to the formation and enrichment history of a stellar population. Here we present an investigation of the Galactic bulge, where we apply principal component abundance analysis (PCAA)---a…

Astrophysics of Galaxies · Physics 2012-08-31 Brett H. Andrews , David H. Weinberg , Jennifer A. Johnson , Thomas Bensby , Sofia Feltzing

For three stars in the ultra-faint dwarf (UFD) galaxy Bootes I we have determined the atmospheric parameters, performed a new reduction of high-resolution spectra from the Subaru archive, and derived the abundances of eight chemical…

Astrophysics of Galaxies · Physics 2019-06-28 Yu. V. Pakhomov , L. I. Mashonkina , T. M. Sitnova , P. Jablonka

We test the capabilities of 0.4 m telescopes equipped with an \'{e}chelle spectrograph to derive fundamental parameters and elemental abundances of four late-B type stars: HR 342, HR 769, HR 1284, and HR 8705. The medium resolution…

Solar and Stellar Astrophysics · Physics 2024-10-01 T. Kılıçoğlu , R. Monier

Elemental abundances of carbon, nitrogen, oxygen, magnesium, aluminum, and silicon are presented for a sample of twelve rapidly rotating OB star (v sin i > 60 km s^-1) members of the Cep OB2, Cyg OB3 and Cyg OB7 associations. The abundances…

Astrophysics · Physics 2009-11-07 Simone Daflon , Katia Cunha , Keith Butler , Verne V. Smith

Barium stars show enhanced abundances of the slow neutron capture (s-process) heavy elements, and for this reason they are suitable objects for the study of s-process elements. The aim of this work is to quantify the contributions of the…

Astrophysics · Physics 2009-11-11 Dinah M. Allen , Beatriz Barbuy

We present elemental abundances of 118 stars (28 of which are known extrasolar planetary host stars) observed as part of the Anglo-Australian Planet Search. Abundances of O, Mg, Cr, Y, Zr, Ba, Nd and Eu (along with previously published…

Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric…

Solar and Stellar Astrophysics · Physics 2015-05-20 Katharina Lodders

Abundances of Li, heavy elements and carbon isotope ratios have been measured in 12 J-type galactic carbon stars. The abundance analysis shows that in these stars the abundances of s-process elements with respect to the metallicity are…

Astrophysics · Physics 2009-10-31 Carlos Abia , Jordi Isern

Although globular clusters are generally chemically homogeneous, substantial abundance variations are sometimes seen even among unevolved main sequence stars, especially for the CNO group of elements. Multi-object intermediate-dispersion…

Astrophysics · Physics 2007-05-23 Russell Cannon , Gary Da Costa , John Norris , Laura Stanford , Barry Croke

Planetary Nebulae (PNe) abundance patterns have long been used to note signatures of nuclear processing and to trace the distribution of metals throughout galaxies. We present abundance gradients and heavy element ratios based upon newly…

Astrophysics · Physics 2009-11-11 J. B. Milingo , K. B. Kwitter , R. B. C. Henry , S. P. Souza

Solar photospheric abundances and CI-chondrite compositions are reviewed and updated to obtain representative solar system abundances of the elements and their isotopes. The new photospheric abundances obtained here lead to higher solar…

Solar and Stellar Astrophysics · Physics 2025-02-18 Katharina Lodders , Maria Bergemann , Herbert Palme

The recently discovered phosphorus-rich stars pose a challenge to stellar evolution and nucleosynthesis theory, as none of the existing models can explain their extremely peculiar chemical abundances pattern. Apart from the large phosphorus…

Solar and Stellar Astrophysics · Physics 2020-11-25 T. Masseron , D. A. García-Hernández , O. Zamora , A. Manchado

We present the first release of a large-scale study of relatively bright (V < 13.5) metal-poor stars observed with the Southern African Large Telescope (SALT), based on high-resolution spectra of 50 stars with a resolving power of R ~…

Observations of hot stars belonging to the young cluster SMC-NGC330 and its surrounding region were obtained with the VLT-GIRAFFE facilities in MEDUSA mode. We investigated the B and Be star properties and proportions in this environment of…

We previously explored the circumstellar effects on the Rb and Zr abundances in massive Galactic O-rich AGB stars. Here we are interested in the role of the extended atmosphere in the case of Li and Ca. Li is an important indicator of HBB…

Solar and Stellar Astrophysics · Physics 2019-03-27 V. Pérez-Mesa , O. Zamora , D. A. García-Hernández , Y. Osorio , T. Masseron , B. Plez , A. Manchado , A. I. Karakas , M. Lugaro

(Abridged) New boron abundances for seven main-sequence B-type stars are determined from HST STIS spectroscopy around the BIII 2066A line. Boron abundances provide a unique and critical test of stellar evolution models that include…

Astrophysics · Physics 2009-11-13 J. T. Mendel , K. A. Venn , C. R. Proffitt , A. M. Brooks , D. L. Lambert