Related papers: Chemical (in)homogeneity and atomic diffusion in t…
The abundance ratios of some chemical species have been found to correlate with stellar age, leading to the possibility of using stellar atmospheric abundances as stellar age indicators. These chemical clocks have been calibrated with…
We present a fully differential chemical abundance analysis using very high-resolution (R >~ 85,000) and very high signal-to-noise (S/N~800 on average) HARPS and UVES spectra of 7 solar twins and 95 solar analogs, 24 are planet hosts and 71…
Galactic chemical evolution (GCE), solar analogues or twins, and peculiarities of the solar composition with respect to the twins are inextricably related. We examine GCE parameters from the literature and present newly derived values using…
Lithium abundances in open clusters provide an effective way of probing mixing processes in the interior of solar-type stars and convection is not the only mixing mechanism at work. To understand which mixing mechanisms are occurring in…
During the past decade, several studies reported a correlation between chemical abundances of stars and condensation temperature (also known as Tc trend). However, the real astrophysical nature of this correlation is still debated. The main…
CONTEXT: [ABRIDGED]. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compare Galactic chemical evolution models to observational data for this still…
The study of star clusters has advanced our understanding of stellar evolution, Galactic chemical evolution and nucleosynthesis. Here we investigate the composition of turn-off stars in the intriguing open cluster, NGC 6791, which is old,…
Solar twins are stars with similar stellar (surface) parameters to the Sun that can have a wide range of ages. This provide an opportunity to analyze the variation of their chemical abundances with age. Nissen (2015) recently suggested that…
Open clusters are one of the best astrophysical laboratories we have available for stellar astrophysics studies. This work presents metallicities and individual abundances for fourteen M dwarfs and six G dwarfs from two well-known open…
Aims. A sample of early B-type stars in OB associations and the field within the solar neighbourhood is studied comprehensively. Present-day abundances for the astrophysically most interesting chemical elements are derived. Methods.…
Using asteroseismic data from the Kepler satellite, we explore the systematic uncertainties arising from changes in the input physics used when constructing evolution models of solar-type stars. We assess the impact of including atomic…
Diffusion of elements in the atmosphere and envelope of a star can drastically alter its surface composition, leading to extreme chemical peculiarities. We consider the case of hot subdwarfs, where surface helium abundances range from…
The Gaia mission has provided highly accurate observations that have significantly reduced the scatter in the colour-magnitude diagrams of open clusters. As a result of the improved isochrone sequence of the open cluster M67, we have…
Chemical composition is an important factor that affects stellar evolution. The element abundance on the stellar surface evolves along the lifetime of the star because of transport processes, including atomic diffusion. However, models of…
Stars observed in the field of an open cluster are ideal for a controlled test of chemical tagging. Using chemical tagging, one should identify the cluster members, i.e., those stars of similar chemical composition, if their composition is…
We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…
Chemical tagging promises to use detailed abundance measurements to identify spatially separated stars that were in fact born together (in the same molecular cloud), long ago. This idea has not yielded much practical success, presumably…
The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets. Here we present high-resolution, high signal-to-noise spectroscopic data for 17 solar-like…
A representative sample of unevolved early B-type stars in nearby OB associations and the field is analysed to unprecedented precision using NLTE techniques. The resulting chemical composition is found to be more metal-rich and much more…
We examine the impact of discrete numbers of stars in stellar populations on the results of Chemical Evolution Models. We explore the resulting dispersion in the true yields and their possible relation with the dispersion in observational…