Related papers: The abundance pattern of the lambda Bootis stars
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…
The precision differential abundance (PDA) technique is applied to the mid-F stars Procyon and $\theta$ Scl using spectra from the ESO UVESPOP library. We relate PDA patterns to endogenous processes related to condensation or to exogenous…
Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high…
We measure chemical abundance ratios and radial velocities in four massive (i.e., young) [alpha/Fe]-rich red giant stars using high-resolution high-S/N spectra from ESPaDOnS fed by Gemini-GRACES. Our differential analysis ensures that our…
Observations and modelling of stars with near-solar masses in their early phases of evolution is critical for a better understanding of how dynamos of solar-type stars evolve. We examine the chemical composition and the spot distribution of…
We present abundance ratios for 23 elements with respect to Fe in a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff, in the globular cluster M71. The analyzed spectra, obtained with HIRES at…
Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features--spectral indices--whose strengths rely on the abundances of one or more elements. Such comparisons hinge…
We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni and Ba for 43 metal-poor field stars in the solar neighbourhood with iron abundances [Fe/H] ranging from -0.4 to -3.0. Total abundance errors are estimated to about…
We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…
Context. Establishing the multiplicity of O-type stars is the first step towards accurately determining their stellar parameters. Moreover, the distribution of the orbital parameters provides observational clues to the way that O-type stars…
We present newly derived stellar parameters and the detailed abundances of 19 elements of seven stars with small planets discovered by NASA's Kepler Mission. Each star save one has at least one planet with a radius <= 1.6 R_Earth,…
12 Bootis is a spectroscopic binary whose visual orbit has been resolved by interferometry. Though the physical parameters of the system have been determined with an excellent precision, the theoretical modelling of the components is still…
We have used high-resolution, high-S/N ratio spectra from the UVES spectrograph at the ESO VLT telescope. Long-term radial-velocity measurements and broad-band photometry allow us to determine improved orbital elements and stellar…
We present abundances of Mn, Cu, Zn and various light and heavy elements for a sample of barium and normal giant stars, and present correlations between abundances contributed to different degrees by the weak-s, main-s, and r-processes of…
Context. Carbon, oxygen and nitrogen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. Aims. We present a detailed spectroscopic…
We performed a uniform and detailed abundance analysis of 12 refractory elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn and V) for a sample of 1111 FGK dwarf stars from the HARPS GTO planet search program. 109 of these stars are known…
Here we aim to understand the origin of 47 Tuc's La-rich star Lee 4710. We report abundances for O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Co, Ni, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, and Eu, and present a detailed abundance analysis of two 47 Tuc…
Spectra from MDM Observatory are used to assess Lick/IDS feature strength gradients inside the half-light radius of the compact Local Group elliptical galaxy M32. All but a few (of 24 measured) indices show a statistically significant…
We present Li abundances for 73 stars in the metallicity range -3.5 < [Fe/H] < -1.0 using improved IRFM temperatures (Casagrande et al. 2010) with precise E(B-V) values obtained mostly from interstellar NaI D lines, and high-quality…
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…