En esta tesis estudiamos la propagación de ondas magneto-acústicas en manchas solares, desde debajo de la fotosfera hasta la cromosfera. La motivación de este estudio va más allá de la simple derivación de las propiedades de las oscilaciones, ya que las ondas pueden ser usadas como herramienta de diagnóstico independiente para derivar la estructura

Extreme ultraviolet (EUV) and X-ray emission is of great importance in several phenomena related to the formation of planetary systems and the atmospheres of planets. The atmospheric composition and the mass of an exoplanet are partly dependent on the X-ray and EUV radiation received during the first stages of formation and even during main

We use N-body simulations to explore the possibility that the Sagittarius (Sgr) dwarf galaxy was originally a late-type, rotating disc galaxy, rather than a non-rotating, pressure-supported dwarf spheroidal galaxy, as previously thought. We find that bifurcations in the leading tail of the Sgr stream, similar to those detected by the SDSS survey

We present the latest analysis and results from SEPPCoN (Survey of Ensemble Physical Properties of Cometary Nuclei). This on-going survey involves studying 100 JFCs - about 25% of the known population - at both mid-infrared and visible wave-lengths to constrain the distributions of sizes, shapes, spins, and albedos of this population. Having

We report on the recent RXTE pointed observations of the the ongoing outburst of the neutron star (NS) transient source in the globular cluster Terzan 5 (Atel #2919, #2920, #2922, #2924, #2929, #2932, #2933, #2937, #2939, #2940, #2946).

We present a stellar population analysis of the absorption line strength maps for 48 early-type galaxies from the SAURON sample. Using the line strength index maps of Hβ, Fe5015 and Mgb, measured in the Lick/IDS system and spatially binned to a constant signal-to-noise ratio, together with predictions from up-to-date stellar population models, we