Available from the Minor Planet Center.

Available from the Minor Planet Center.

The near 155 days solar periodicity, so called Rieger periodicity, was first detected in solar flares data and later confirmed with other important solar indices. Unfortunately, a comprehensive analysis on the occurrence of this periodicity during previous centuries can be further complicated due to the poor quality of the sunspot number time

Esta tesis consta de dos partes: una científica en la que con de datos espectroscópicos y fotométricos, se derivan la distribución de metalicidad, las propiedades a gran escala de la extinción infrarroja y la distribución estelar en el interior de la Vía Láctea; y una instrumental en la que se caracteriza el detector de EMIR, instrumento que nos

We present a study of the bar fraction in the Coma Cluster galaxies based on a sample of ~190 galaxies selected from the Sloan Digital Sky Survey Data Release 6 and observed with the Hubble Space Telescope (HST) Advanced Camera for Survey (ACS). The unprecedented resolution of the HST-ACS images allows us to explore the presence of bars, detected

The dust complex G159.6-18.5 in the Perseus region has previously been observed with the COSMOSOMAS experiment on angular scales of ~1°, and was found to exhibit anomalous microwave emission. We present the first high angular resolution observations of this dust complex, performed with the Very Small Array (VSA) at 33GHz, to help increase the