We present the concept of a novel facility dedicated to massively-multiplexed spectroscopy. The telescope has a very wide field Cassegrain focus optimised for fibre feeding. With a Field of View (FoV) of 2.5 degrees diameter and a 11.4m pupil, it will be the largest etendue telescope. The large focal plane can easily host up to 16.000 fibres. In addition, a gravity invariant focus for the central 10 arc-minutes is available to host a giant integral field unit (IFU). The 3 lenses corrector includes an ADC, and has good performance in the 360-1300 nm wavelength range. The top level science requirements were developed by a dedicated ESO working group, and one of the primary cases is high resolution spectroscopy of GAIA stars and, in general, how our Galaxy formed and evolves. The facility will therefore be equipped with both, high and low resolution spectrographs. We stress the importance of developing the telescope and instrument designs simultaneously. The most relevant R&D aspect is also briefly discussed.

We have used archival Hubble Space Telescope (HST) observations obtained with the Advanced Camera for Surveys (ACS) to study the Hα emission properties of main sequence (MS) stars in the globular cluster 47 Tucanae. An accurate photometric measurement of their Hα equivalent width, allows us to identify objects with large Hα emission. We demonstrate that this method allows us to identify and characterise candidate cataclysmic variables (CVs) with high efficiency, reconciling observations with theoretical predictions on the number of dynamically formed CVs expected in a 47 Tucanae-like globular cluster.

I review the instrumentation plans of the future ELT projects, with particular emphasys on one category of instruments which will be particularly relevant for this Symposium community: high resolution spectrographs.

The aim of this work is the investigation of the metal-hydride transformation in magnesium (Mg) nanoparticles both as a function of particle size and in response to surface functionalization by clusters of transition metals (TM): Pd, Ni, Ti.

Mg nanoparticles were synthesized by the inert-gas condensation technique, which yields single crystals with six-fold symmetry whose average size can be controlled by tuning the inert gas pressure. After the synthesis the nanoparticles were passivated by slow exposure to oxygen, obtaining a core-shell morphology where a metallic core is coated by a MgO shell of about 5 nm thickness.

The material structure was investigated by Transmission Electron Microscopy (TEM), also in High Resolution (HRTEM) mode, and by X-Ray Diffraction (XRD). The sorption kinetics were analysed by a volumetric Sievert apparatus, which also allowed for a determination of the activation energies.

Small nanoparticles (≈35 nm) display interesting kinetics with gravimetric capacity of 4.5 wt.% at saturation, limited by the oxide fraction. Hydride formation proceeds by one-dimensional growth controlled by diffusion through the hydride, while the reverse transformation to metal involves interface-controlled three-dimensional growth of nuclei formed at constant rate.

On the contrary, large nanoparticles (≈450 nm) exhibit very low reactivity due to reduced probability of hydrogen dissociation/recombination and nucleation at the particle surface. For this reason, large nanoparticles were surface-decorated by TM through in situ evaporation in the inert-gas condensation chamber. This procedure results in clusters of 3-4 nm located over a portion of the MgO shell, as shown by XRD and HRTEM on Pd-decorated sample. This treatment results in dramatically improved hydrogen sorption behavior. In fact, previously inert nanoparticles now exhibit of up to 5.6 wt.%.

Real-time diffraction studies using Synchrotron Radiation were carried out during hydrogen desorption on the Pd-decorated nanoparticles. We clearly show that a Mg-Pd intermetallic phase is formed after the first heating treatment and takes active part in the transformation.

We use Beryllium to investigate star formation in the early Galaxy. Be has been demonstrated to be a good indicator of time in these early epochs. By analyzing the so-far largest sample of halo and thick disk metal poor stars, we find a clear scatter in Be for a given value of [Fe/H] and [O/H]. The scatter is very pronounced for Halo stars, while it is marginal for thick disk stars. Our halo stars separate in the [α/Fe] - Be diagram, showing two main branches: one indistinguishable from the thick disk stars, and one with lower [α/Fe] ratio. The stars belonging to this branch are characterized by highly eccentric orbits and small perigalactic radius (Rmin). Their kinematics are consistent with an accreted component.

Planet searches around evolved giant stars are bringing new insights to planet formation theories by virtue of the broader stellar mass range of the host stars compared to the solar-type stars that have been the subject of most current planet searches programs. These searches among giant stars are producing extremely interesting results. Contrary to main sequence stars planet-hosting giants do not show a tendency of being more metal rich. Even if limited, the statistics also suggest a higher frequency of giant planets (at least 10%) that are more massive compared to solar-type main sequence stars.

The interpretation of these results is not straightforward. We propose that the lack of a metallicity-planet connection among giant stars is due to pollution of the star while on the main sequence, followed by dillution during the giant phase. We also suggest that the higher mass and frequency of the planets are due to the higher stellar mass. Even if these results do not favor a specific formation scenario, they suggest that planetary formation might be more complex than what has been proposed so far, perhaps with two mechanisms at work and one or the other dominating according to the stellar mass. We finally stress as the detailed study of the host stars and of the parent sample is essential to derive firm conclusions.

Inert gas condensation was employed to prepare nanoparticles of Mg and MgH2 which morphology, clustering degree and structural stability have been investigated by X-ray diffraction and electron microscopy. Thermodynamic functional properties of the Mg and MgH2 nanostructured samples were investigated by high pressure differential scanning calorimetry. Some specific features of the morphology of the samples prepared by inert gas condensation are compared with powders obtained by ball milling through desorption kinetics behavior.

The microstructure and hydrogen sorption behaviour of MgH2 based nano-hydrides with different additives prepared by ball milling and inert gas condensation has been investigated by XRD, Differential Scanning Calorimetry and Mechanical Spectroscopy. Preliminary results on materials with similar composition and different nanostructures show that suitable mechanical processing and additive additions induce in the nanostructured composites tailored channels for improved ab/de-sorption kinetics at reduced temperatures.

The combination of the collecting power of an ELT with an ultra-stable high resolution spectrograph opens up the possibility to measure for the first time directly the dynamical effect of the acceleration of the Universe. CODEX will also provide unique opportunities for advance in many other branches of astrophysics. The CODEX design is based on an array of several identical spectrographs. It is highly modular and can be easily adapted to a large range of sky apertures and telescope diameters. CODEX is designed to work as a seeing limited instrument. The requirements for the telescope are moderate and clearly identified.

Lithium abundance in Turnoff stars of Globular Clusters (GC) provide precious information about primordial nucleosynthesis and Globular Cluster formation. Out of the three GC so far observed in some detail, the metal poor NGC6397 shows a constant Li abundance, at the same level of the Spite' plateau; while the more metal rich NGC6752 and 47 Tuc show a beautiful Li-Na anticorrelation (the first of this kind observed in PoP II stars), suggesting the presence of gas processed by a previous generation of stars. These observations are quite puzzling: while they are qualitatively compatible with the scenario of contamination from intermediate mass AGB stars, no progenitor can quantitatively reproduce the observations. Beryllium has also been detected in NGC6397 Turnoff stars, indicating that the gas which formed the stars was exposed for about 200 Myr to the Galactic Cosmic Rays. The emerging picture seems to require that in the early Galaxy both local (SNae, AGB stars) and global (Galactic Cosmic Rays) enrichment processes were acting simultaneously in the star formation phase of the halo.

The study of Li in Pop I stars has focussed in the last years on observations of open clusters, spanning a large range of ages and metallicities. So far the observational picture is quite complex: the data indicate several phenomena which are not well understood, from the 'Li dip', to the scatter in Li abundances found among (otherwise similar) stars both in young and old clusters. Models fail in reproducing most of the observed features; in particular the almost total lack of dependence of Li depletion with metallicity. The comparison between clusters of different ages show that no PMS depletion occurs, and that for a large fraction of old star no additional depletion occurs after the first ˜1.5 Gyrs, while the depletion is strong at earlier ages. These observations are crucial for our understanding of the relationship between the Pop II Li Plateau and the Li primordial abundance.