At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u ~ 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy

We present the results of a dedicated search for extremely metal-poor stars in the Fornax, Sculptor, and Sextans dSphs. Five stars were selected from two earlier VLT/Giraffe and HET/HRS surveys and subsequently followed up at high spectroscopic resolution with VLT/UVES. All of them turned out to have [Fe/H] ⪉ -3 and three stars are below [Fe/H] ~

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space Agency ESA. CoRoT observed since its launch in December 27, 2006 about 100 000 stars for the exoplanet channel, during 150 days uninterrupted high

Las estrechas relaciones existentes entre parámetros fundamentales de galaxias, tanto espirales como elípticas, son un reflejo de su formación y evolución. Concretamente, la relación de Tully-Fisher y el Plano Fundamental son un indicativo de la relación existente entre la masa total y la masa luminosa de las galaxias. Ambas relaciones han sido de

This thesis was devoted to the study of clusters and superclusters of galaxies. In particular, those that show a detectable Sunyaev-Zeldovich (SZ) effect. We aimed to fully characterize these structures and the relative contributions that their physical components (diffuse and collapsed phases) play in building up the total Sunyaev-Zeldovich signal