A comparison is made of the light curves and and dust production of the initial target for the ROSETTA mission, 46P/Wirtanen and the new target 67P/Churyumov-Gerasimenko during their recent 2002/2003 apparition. The study is based on amateur CCD monitoring using a standardised method to produce consistent photometry in Johnson-Kron-Cousins system

La tesis está dividido en dos partes, si bien muy relacionadas. En la primera parte se desarrolla y aplica un método para detectar sistemas de galaxias en el óptico 0.2

Rucinski (1996) suggested to use contact binary stars as standard candles. We investigated the properties of contact binary stars in order to search for possibility of their using as standard candles. For this purpose a catalogue of their light curve solution was compiled and on the basis of the catalogue data we calculated the rate of energy

We consider stochastically quantized self-interacting scalar fields as suitable models to generate dark energy in the Universe. Second quantization effects lead to new and unexpected phenomena if the self-interaction strength is strong. The stochastically quantized dynamics can degenerate to a chaotic dynamics conjugated to a Bernoulli shift in

The Wide Field Cameras onboard BeppoSAX observed 9 type I X-ray bursters without detectable persistent emission around the burst. According to the standard theory of X-ray bursts these sources should be in the lowest mass-accretion regime, opening the possibility to study this regime for the first time. We compare the sources with the burst theory

During the whole operational lifetime of the BeppoSAX X-ray satellite, the Galactic bulge region was monitored in the 2-28 keV band through dedicated observational campaigns and serendipitous secondary pointings by the Wide Field Cameras. Since the high mass binary 4U 1700-377 was in the field of view whenever a Camera pointed to the Galactic