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Related papers: HE 0557-4840 - Ultra-Metal-Poor and Carbon-Rich

200 papers

We present the discovery of 2MASS J05241392-0336543 (hereafter J0524-0336), a very metal-poor ([Fe/H]=-2.43 +- 0.16), highly r-process-enhanced ([Eu/Fe]= +1.34 +- 0.10) Milky Way halo field red giant star, with an ultra high Li abundance of…

We present a sample of 1777 bright (9<B<14) metal-poor candidates selected from the Hamburg/ESO Survey (HES). Despite saturation effects present in the red portion of the HES objective-prism spectra, the data were recoverable and…

We present a detailed abundance analysis of 23 elements for a newly discovered carbon-enhanced metal-poor (CEMP) star, HE 0414-0343, from the Chemical Abundances of Stars in the Halo (CASH) Project. Its spectroscopic stellar parameters are…

The carbon-enhanced metal-poor star BD+44 493 ([Fe/H]=-3.9) has been proposed as a candidate second-generation star enriched by metals from a single Pop III star. We report the first detections of P and S and the second detection of Zn in…

Solar and Stellar Astrophysics · Physics 2016-06-22 Ian U. Roederer , Vinicius M. Placco , Timothy C. Beers

We present the chemical compositions of four K giants CS 22877-1, CS 22166-16, CS22169-35 and BS 16085 - 0050 that have [Fe/H] in the range -2.4 to -3.1. Metal-poor stars with [Fe/H] < -2.5 are known to exhibit considerable star - to - star…

Astrophysics · Physics 2009-11-06 Sunetra Giridhar , David L. Lambert , Guillermo Gonzalez , Gajendra Pandey

There is an apparent dichotomy between the metal-poor ([Fe/H] <= -2) yet carbon-normal giants and their carbon-rich counterparts. The former undergo significant depletion of carbon on the red giant branch after they have undergone first…

Solar and Stellar Astrophysics · Physics 2015-05-13 Richard J. Stancliffe , Ross P. Church , George C. Angelou , John C. Lattanzio

Carbon-enhanced metal-poor (CEMP) stars span a wide range of stellar populations, from bona fide second-generation stars to later forming stars that provide excellent probes of, e.g., binary mass transfer. Here we analyse 11 metal-poor…

We report on the first high-resolution spectroscopic analysis of HE0020-1741, a bright (V=12.9), ultra metal-poor ([Fe/H] = -4.1), carbon-enhanced ([C/Fe] = +1.7) star selected from the Hamburg/ESO Survey. This star exhibits low abundances…

We examine the mid-infrared fluxes and spectral energy distributions for metal-poor stars with iron abundances [Fe/H] $\lesssim-5$, as well as two CEMP-no stars, to eliminate the possibility that their low metallicities are related to the…

Solar and Stellar Astrophysics · Physics 2015-06-22 Kim A. Venn , Thomas H. Puzia , Mike Divell , Stephanie Cote , David L. Lambert , Else Starkenburg

An abundance analysis for the carbon-enhanced, extremely iron-poor ([Fe/H] -3.5) star CS29498-043 has been obtained using new high-resolution, high signal-to-noise spectra from the Subaru Telescope. The [O I] forbidden line at 6300A and the…

We present high-resolution Magellan/MIKE spectroscopy of the brightest star in the ultra-faint dwarf galaxy Leo IV. We measure an iron abundance of [Fe/H] = -3.2, adding to the rapidly growing sample of extremely metal-poor stars being…

Astrophysics of Galaxies · Physics 2015-05-18 Joshua D. Simon , Anna Frebel , Andrew McWilliam , Evan N. Kirby , Ian B. Thompson

HE 0107$-$5240 is a hyper metal-poor star with $\rm [Fe/H]=-5.39$. We performed high-res observations with the ESPRESSO spectrograph at the VLT to constrain the kinematical properties of the binary system HE 0107$-$5240 and to probe the…

We present an abundance analysis for the extremely metal poor star HE1424-0241 based on high dispersion spectra from HIRES at Keck. This star is a giant on the lower red giant branch with [Fe/H] ~ -4.0 dex. Relative to Fe, HE1424-0241 has…

We present the first time abundance analysis of a very metal-poor carbon-enhanced star CD-27 14351 based on a high resolution (R ~ 48000) FEROS spectrum. Our abundance analysis performed using Local Thermodynamic Equilibrium (LTE) model…

Solar and Stellar Astrophysics · Physics 2017-01-11 Drisya Karinkuzhi , Aruna Goswami , Thomas Masseron

The chemical composition of stars with extremely low metal contents (taking ``metals'' to mean all elements other than hydrogen and helium) provides us with information on the masses of the stars that produced the first metals. Such a…

Astrophysics · Physics 2015-06-24 Piercarlo Bonifacio , Marco Limongi , Alessandro Chieffi

We present elemental abundances for eight unevolved extremely metal-poor stars with $T_{\rm eff}>5500\,\mathrm{K}$, among which seven have $[\mathrm{Fe/H}]<-3.5$. The sample is selected from the Sloan Digital Sky Survey / Sloan Extension…

Solar and Stellar Astrophysics · Physics 2017-07-26 Tadafumi Matsuno , Wako Aoki , Timothy C. Beers , Young Sun Lee , Satoshi Honda

Very metal-deficient stars that exhibit enhancements of their carbon abundances are of crucial importance for understanding a number of issues -- the nature of stellar evolution among the first generations of stars, the shape of the Initial…

Astrophysics · Physics 2009-11-10 B. Marsteller , T. C. Beers , S. Rossi , N. Christlieb , M. Bessell , J. Rhee

We present a comprehensive chemical abundance analysis of five red giants and two horizontal branch (HB) stars towards the southern Galactic bulge, at (l,b)$\sim$(0$^{\rm o}$,-11$^{\rm o}$). Based on high-resolution spectroscopy obtained…

Astrophysics of Galaxies · Physics 2016-03-16 Andreas Koch , Andrew McWilliam , George W. Preston , Ian B. Thompson

The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions that are close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or few supernovae. Only…

It has been proposed theoretically that the first generation of stars in the Universe (population III) would be as massive as 100 solar masses (100Mo), because of inefficient cooling of the precursor gas clouds. Recently, the most…

Astrophysics · Physics 2015-06-24 Hideyuki Umeda , Ken'ichi Nomoto