Measured the amount of plasma between 10000 and 30 million degrees—responsible for the emission of extreme UV radiation and soft X-rays—in a sample of Sun-like and low-mass stars. Sun-like stars (spectral classes FGK) and low-mass stars (spectral class M) host in their outer atmospheres (the corona) plasma at temperatures of millions of degrees. Such high temperatures are reached through
Several astronomical studies rely on the precise determination of the chemical abundances of stars. For instance, the determination of chemical abundances of stars in different sites of the Milky Way, or with different age or evolutionary phase, can provide precious information on the evolution of our Galaxy. However, recently it has been discovered that spectroscopic determination of stellar chemical abundances
The intensity of Solar magnetic activity and of the related phenomena (such as sunspots and flares) varies with an 11-years cycle. In order to understand whether such an activity cycle is common among solar-type stars, since 1966 a project based on the Observatory of Mt. Wilson is collecting measurements of the cromospheric activity of a large sample of low-mass stars
The study of the chemical abundances of stars with different age and position in the Milky Way provide crucial information on the formation and evolution of our Galaxy. In particular, heavy elements (i.e. those with the atomic number Z > 30) are produced by the successive capture of neutrons by lighter elements. This occurs by two processes, the slow s-process
E’ stato recentemente pubblicato su Monthly Notices of the Royal Astronomical Society l’articolo “The Gaia-ESO Survey: lithium depletion in the Gamma Velorum cluster and inflated radii in low-mass pre-main-sequence stars” di R. D. Jeffries, con vari coautori dell’Osservatorio Astronomico di Palermo. L’articolo nasce dal progetto internazionale “The Gaia-ESO survey“, che vede un forte coinvolgimento dell’Osservatorio Astronomico di Palermo. Nell’articolo
