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A 50 min time series of one-dimensional slit-spectrograms, taken in quiet sun at disk centre, observed at the German Vacuum Tower Telescope (Observatorio del Teide), was used to study the global and spatial variations of different line parameters. In order to determine the vertical structure of the photosphere two lines with well separated

We present time-resolved optical spectroscopy and photometry, and far-ultraviolet spectroscopy of HS 0728+6738, a cataclysmic variable discovered in the Hamburg Quasar Survey. We show that the system is a new eclipsing member of the SW Sex class of CVs with an orbital period of 3.21 h. We derive an orbital inclination of ˜ 85 ± 4° from the average

Several works have recently shown that there is an important extra line-broadening (usually called macroturbulence) affecting the spectra of O and B Supergiants that adds to stellar rotation. So far, the only (very recent) physical explanation for the appearance of macroturbulence relates to oscillations. This is a plausible explanation, but no

Sir The toxic spill by the mining company Boliden into the Guadiamar River and the Doñana Natural Park last April highlighted the lack of co-ordination between Spain's central and regional administrations, and their incapacity to deal efficiently with major environmental hazards. This disastrous event has once more stressed the necessity for more

Context. Lithium-rich giant stars are rare objects. For some of them, Li enrichment exceeds the abundance of this element found in solar system meteorites, suggesting that these stars have gone through a Li enhancement process. Aims: We identified a Li-rich giant HD 107028 with A(Li) > 3.3 in a sample of evolved stars observed within the PennState