Related papers: Does the i-process operate at nearly solar metalli…

In this work, we study the chemical compositions and kinematic properties of six metal-poor stars with [Fe/H] $< -2.5$ in the Galactic halo. From high-resolution (R $\sim$~110,000) spectroscopic observations obtained with the Lick/APF, we…

We study s-process element abundance ratios in stars by carrying out stellar population synthesis, using a rapid synthetic stellar evolution code which includes an up-to-date treatment of AGB nucleosynthesis and evolution. In contrast to…

We present a detailed analysis of the composition and nucleosynthetic origins of the heavy elements in the metal-poor ([Fe/H]=-1.62+/-0.09) star HD94028. Previous studies revealed that this star is mildly enhanced in elements produced by…

Well-studied very metal-poor (VMP, [Fe/H] < -2 ) stars in the inner Galaxy are few in number, and they are of special interest because they are expected to be among the oldest stars in the MilkyWay. We present high-resolution spectroscopic…

Abundances of low-metallicity stars offer a unique opportunity to understand the contribution and conditions of the different processes that synthesize heavy elements. Many old, metal-poor stars show a robust abundance pattern for elements…

We report on a detailed abundance analysis of two strongly r-process enhanced, very metal-poor stars newly discovered in the HERES project, CS 29491-069 ([Fe/H]=-2.51, [r/Fe]=+1.1) and HE 1219-0312 ([Fe/H]=-2.96, [r/Fe]=+1.5). The analysis…

Barium (Ba) stars help to verify asymptotic giant branch (AGB) star nucleosynthesis models since they experienced pollution from an AGB binary companion and thus their spectra carry the signatures of the slow neutron capture process (s…

We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy…

Ground- and space-based observations of stellar heavy element abundances are providing a clearer picture of the chemical evolution of the Galaxy. A large number of (r)apid and (s)low neutron capture process elements, including the first…

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…

The chemical abundances of metal-poor stars provide important clues to explore stellar formation history and set significant constraints on models of the r-process. In this work, we find that the abundance patterns of the light and iron…

We present an abundance analysis of the very metal-poor, carbon-enhanced star CS 29497-030. Our results indicate that this unusually hot turnoff star (Teff = 6650K, log g = 3.5) has a metallicity [Fe/H] = -2.8, and exhibits large…

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…

In an effort to extend the still limited sample of s-process enriched post-AGB stars, high-resolution, high signal-to-noise VLT+UVES spectra of the optical counterparts of the infrared sources IRAS06530-0213 and IRAS08143-4406 were…

Accurate relative abundances have been obtained for a sample of 21 mildly metal-poor stars from the analysis of high resolution and high signal-to-noise spectra. With these accurate results, correlations between relative abundances have…

We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B < 14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was only…

Historically, the weak s-process contribution to metal-poor stars is thought to be extremely small, due to the effect of the secondary-like nature of the neutron source 22Ne(a;n)25Mg in massive stars, which means that metal-poor weak…

We present detailed abundance results based on UVES high dispersion spectra for 7 very and extremely metal-poor stars in the Large Magellanic Cloud. We confirm that all 7 stars, two of which have [Fe/H] $\leq$ --3.0, are the most metal-poor…

We present the first calculations to follow the evolution of all stable isotopes (and their abundant radioactive progenitors) in a finely zoned stellar model computed from the onset of central hydrogen burning through explosion as a Type II…

Individual mainstream stardust silicon carbide (SiC) grains and a SiC-enriched bulk sample from the Murchison carbonaceous meteorite have been analyzed by the Sensitive High Resolution Ion Microprobe - Reverse Geometry (SHRIMP-RG) for Eu…