First results from the AGN-Heidelberg program aimed at resolving the central pc region of the closest Active Galactic Nuclei in the IR are presented. The core region of prototype active nuclei are clearly unveiled at IR waves and at distances from the nucleus - few pc- where circumnuclear starforming regions appear not to be present. Within that

Absorption line-strengths have allowed us to carry out a comprehensive stellar populations analysis, providing very strong constraints for discriminating and constraining current galaxy formation scenarios. I describe the main features of this approach, pinpointing the most popular indices and diagnostic diagrams, and the main problems affecting

We present the first deep, optical, wide-field imaging survey of the young open cluster Collinder 359, complemented by near-infrared follow-up observations. This study is part of a large programme aimed at examining the dependence of the mass function on environment and time. We have surveyed 1.6 square degree in the cluster in the I and z filters

We report the results of a deep photometric search for planets and brown dwarfs in the nearby young OB Upper Scorpius association. We obtained optical (I) and near-infrared (JK_s) images around nine very low-mass stars and brown dwarf member candidates of the association, covering a total area of 113 arcmin^2. Using a point spread function

The population of high-energy and very high-energy γ-ray sources, detected with EGRET and the new generation of ground-based Cherenkov telescopes, forms a reduced but physically important sample. Most of these sources are extragalactic (e.g. blazars), while among the galactic ones there are pulsars and supernova remnants. The microquasar LS 5039

It is essential to properly calibrate the polarimetric properties of telescopes, if one wants to take advantage of the capabilities of high precision spectro-polarimeters. We have constructed a model for the German Vacuum Tower Telescope (VTT) that describes its time-dependent polarization properties. Since the coelostat of the telescope changes