We present a Chandra X-ray observation of the Galactic globular cluster NGC 2808. Previous observations with XMM-Newton and ultraviolet observations with the Hubble Space Telescope are re-investigated to help identify the Chandra sources associated with the cluster. This data is used to identify the faint X-ray sources belonging to this globular

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Context: Over the past years, the λ-Orionis cluster has been a prime location for the study of young very low mass stars, substellar and isolated planetary mass objects and the determination of the initial mass function and other properties of low mass cluster members. Aims: In the continuity of our previous studies of young associations cores, we

Con el trabajo desarrollado para esta tesis hemos contribuido a un avance en la investigacion de exoplanetas, obteniendo resultados muy interesantes e innovadores que nos han permitido llegar a las siguientes conclusiones: Mediante las observaciones llevadas a cabo con la red TrES, y el nodo canario STARE, y su seguimiento posterior, hemos

Context: Determining the parameters of massive stars is crucial to understand many processes in galaxies and the Universe, since these objects are important sources of ionization, chemical enrichment and momentum. 10m class telescopes enable us to perform detailed quantitative spectroscopic analyses of massive stars in other galaxies, sampling

We present an examination of high-resolution, ultraviolet (UV) spectroscopy from Hubble Space Telescope of the photospheric spectrum of the O-supergiant in the massive X-ray binary HD 226868 = Cyg X-1. We analyzed this and ground-based optical spectra to determine the effective temperature and gravity of the O9.7 Iab supergiant. Using non-LTE, line