The He I triplet at 10830 Å has a great potential for determining the magnetic field vector in the upper chromosphere. The triplet is Zeeman sensitive (Landé factors 2.0, 1.75 and 1.25) and shows the signature of the Hanle effect under appropriate conditions. Additionally, the Zeeman sublevels are influenced by the Paschen-Back effect leading to

We present the results of an on-going program for the identification and characterization of optical counterparts of Ultra-Luminous X-ray (ULX) sources. The targets have been selected from the catalogues by Colbert & Ptak (2002) and Swartz et al. (2004). A clear identification based on unambiguous optical spectral features was possible for 26

Planetary Nebula (PN) shells and AGB circumstellar envelopes evolve under a wide range of external conditions, from the high ISM densities found in the Galactic plane, to the rarefied and hot intracluster medium where the systemic velocity of the star can be as high as 2000 km s-1. We explore the effects that the external pressure and/or stellar

We use UVES spectroscopy of PB 6 to study the variation of its physical conditions as a function of position including: temperature, density, chemical composition and velocity. We present preliminary results from this work. In particular we want to find the relevance of the contribution of the wind from the central star to the chemical composition

High resolution observations of a very quiet region of the solar surface have been obtained with IBIS (Interferometric BIdimensional Spectrometer) in the non-magnetic Fe I 7090.4 Å spectral line. We present a first comparison between the observed, spatially resolved, spectral data and the simulated spectra in a 3D snapshot of a radiation

On July 4 2005 the NASA spacecraft Deep Impact delivered an impactor on the comet 9P Tempel 1 to study the material underneath the surface of the nucleus A worldwide observation campaign accompanied the mission to characterize the activity of Tempel 1 before and after the impact At La Palma Canary Islands the comet was observed from July 2 to July