We have developed TGMETalpha in order to determine T[eff], logg, [Fe/H] and [alpha/Fe] for large samples of FGK stars observed at various spectral resolutions. Tests on several hundred echelle spectra of reference stars degraded at low resolution (R=1.000) have provided typical rms precisions of sigma_ T [eff]~150 K, sigma_logg~0.44, sigma_[Fe/H]~0

Unification schemes of active galactic nuclei (AGN) account for a variety of observational differences in terms of viewing geometry. However, our recent work instead shows tantalizing hints that strong unification may not hold, and that the immediate dusty surroundings of various classes of AGN are intrinsically different. Here we propose to obtain

We have been testing at laboratory commercial variable attenuators commonly used in telecommunication applications for their used in astronomy. Such variable attenuators are going to be included in the central fibers of the integral field unit (IFU) of the prototype instrument EDiFiSE (Equalized and Diffraction-limited Field Spectrograph Experiment

Microvariability consists of small timescale variations of low amplitude in the photometric light curves of quasars and represents an important tool to investigate their inner core. Detection of quasar microvariations is challenging because of their non-periodicity, as well as the need for high monitoring frequency and a high signal-to-noise ratio

A-type asteroid (1951) Lick has a very red visible and near-infrared reflectance spectrum, and it is one of the reddest Near-Earth objects. Its surface is probably affected by heavy space weathering processes. We investigate the possibility of a weathering saturation regime. We compare Lick's spectrum with those of silicate olivine after laser

Context. Dynamically, 133P/Elst-Pizarro and 176P/LINEAR are main belt asteroids, likely members of the Themis collisional family, and unlikely of cometary origin. They have been observed with cometary-like tails, which may be produced by water-ice sublimation. They are part of a small group of objects called Main Belt Comets (MBCs, Hsieh & Jewitt