We obtained simultaneously recorded time series of broadband images of a sunspot close to the disk center at the German Vacuum Tower Telescope, Tenerife, in two wavelength bands at 0.56 μm and 1.55 μm. Maps of brightness difference images Tb(1.55 μm) and Tb(0.56 μm) were computed for the best image pairs. Furthermore, a scatter plot of the

We have analyzed six OB supergiants and one giant covering spectral types from O3 to B1 in the Galactic OB association Cyg OB2 by means of an updated version of FASTWIND (Santolaya-Rey et al. cite{sph97}) that includes an approximate treatment of metal line blocking and blanketing. This large coverage in spectral type allows us to derive a new

Between October 1999 and October 2000 an undistinguished high-galactic latitude patch of sky, the Hubble Deep Field South (HDF-S), was observed with the VLT for more than 100 hours under the best seeing conditions. Using the near-infrared (NIR) imaging mode of the Infrared Spectrometer and Array Camera (ISAAC, Moorwood 1997), we obtained ultradeep

At this meeting we presented a spinfoam model in which the fundamental "bubble amplitudes" (the analog of the one-loop corrections in QFT) are finite as the cutoff is removed. The model is a natural variant of the field theoretical formulation of the Barrett-Crane model. As the last, the model is a quantum BF theory plus an implementation of the

Some observations suggest that quiescent solar prominences can be considered as composed by small-scale loops, or fibrils, which are stacked one after another in both the vertical and horizontal directions. In a previous work we studied, in Cartensian geometry, the propagation of fast MHD waves in a two-dimensional magnetostatic model representing

I present our recent results on bulge evolution. (1) We have modeled the accretion of satellite galaxies onto disk-bulge-halo galaxies, and show that accretion-driven bulge growth generates two of the observed trends of galaxies along the Hubble sequence, namely the higher Sersic index toward more massive bulges, and the appearance of a thick disk