6 papers
Abundance ratios of volatile vs. refractory elements: hints of pollutions?
A. Ecuvillon, G. Israelian, N. C. Santos +2
We present the abundance ratios [X/H] of a large set of chemical species with condensation temperatures from 75 to 1600 K in an almost complete set of 105 planet-host stars and in…
Abundances in stars with exoplanets
Garik Israelian
Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtl…
The Millennium Outburst of the Cool Hypergiant Rho Cassiopeiae: Spectroscopy and Modeling
A. Lobel, A. K. Dupree, R. P. Stefanik +7
Between 2000 June and September an exceptional variability phase occurred in the peculiar F-type hypergiant Rho Cas, when the V-brightness dimmed by at least a full magnitude. The…
Confirming the Metal-Rich Nature of Stars with Giant Planets
Nuno C. Santos, Garik Israelian, Michel Mayor
With the goal of confirming the metallicity ``excess'' observed in stars with planetary mass companions, we have conducted a high-precision spectroscopic study of a ``comparison''…
Chemical analysis of 8 recently discovered extra-solar planet host stars
N. C. Santos, G. Israelian, M. Mayor
We present the chemical analysis of a new set of stars known to harbor low mass companions, namely HD 1237, HD 52265, HD 82943, HD 83443, HD 169830, and HD 202206. In addition, we…
Galactic Evolution of Beryllium and Oxygen
Garik Israelian, Ramon Garcia Lopez, Rafael Rebolo
We discuss the early evolution of beryllium and oxygen in our Galaxy by comparing abundances of these elements for halo and disk metal-poor stars. Both, O and Be rise as we go prog…