Dwarf galaxies, as the most numerous type of galaxy, offer the potential to study galaxy formation and evolution in detail in the nearby universe. Although they seem to be simple systems at first view, they remain poorly understood. In an attempt to alleviate this situation, the MAGPOP EU Research and Training Network embarked on a study of dwarf

We present the first detailed abundance analysis of the metal-poor giant HK-II 17435-00532. This star was observed as part of the University of Texas Long-Term Chemical Abundances of Stars in the Halo (CASH) Project. A spectrum was obtained with the High Resolution Spectrograph (HRS) on the Hobby-Eberly Telescope with a resolving power of R~15000

Two of the most attractive spectral windows for spectropolarimetric investigations of the physical properties of the plasma structures in the solar chromosphere and corona are the ones provided by the spectral lines of the He I 10830 and 5876 Å (or D3) multiplets, whose polarization signals are sensitive to the Hanle and Zeeman effects. However, in

We present new high-resolution near-IR spectroscopy and OH maser observations to investigate the population of cool luminous stars of the young massive Galactic cluster RSGC1. Using the 2.293 μm CO band-head feature, we make high-precision radial velocity measurements of 16 of the 17 candidate red supergiants (RSGs) identified by Figer et al. We

We present a new method to derive the age of young (

A series of recent studies has placed the best estimates of the photospheric abundances of carbon and oxygen at log ɛ =8.39 and 8.66, respectively. These values are ˜ 40 % lower than earlier estimates. A coalition of corrections due to the adoption of an improved model atmosphere, updated atomic data and non-LTE corrections, and a reevaluation of