The magnetic properties of the quiet Sun are investigated using a novel inversion code, FATIMA, based on the Principal Component Analysis of the observed Stokes profiles. The stability and relatively low noise sensitivity of this inversion procedure allows for the systematic inversion of large data sets with a very weak polarization signal. Its

We have imaged an empty area of 34×34 arcmin2 1.5d north of the Virgo Cluster core to survey for intracluster planetary nebula (PN) candidates. We have implemented and tested a fully automatic procedure for the selection of emission-line objects in wide-field images, based on the on-off technique from Ciardullo and Jacoby. Freeman et al. have

We are carrying out a systematic study of the ensuremath {{H}alpha } emission line profiles from the H II regions in NGC 1530 (Knapen et al. 2001) based on a data cube from the TAURUS Fabry-Perot scanner, on the 4.2m WHT, La Palma. The data are of high S:N ratio, high spatial resolution (seeing ~ 0.6 arcsec ) and velocity resolution, FWHM, of 18

ES BIEN SABIDO QUE LA TURBULENCIA ATMOSFÉRICA LIMITA LAS PRESTACIONES DE LOS GRANDES Y EXTRA-GRANDES TELESCOPIOS POR ELLO ES IMPRESCINDIBLE DESARROLLAR ESTRATEGIAS E INSTRUMENTOS QUE SOSLAYEN ESTA LIMITACIONES. LA SOLUCIÓN PASA POR GENERAR ESTRELLAS ARTIFICIALES POR LASER, YA SEA EN LAS CAPAS BAJAS POR SCATTERING RAYLEYGH O EN LA MESOPAUSA A PARTIR

We report in this paper on the design and progress of the ESO Laser Guide Star Facility. The project will create a user facility embedded in UT4, to produce in the Earth's Mesosphere Laser Guide Stars, which extend the sky coverage of Adaptive Optics systems on the VLT UT4 telescope. Embedded into the project are provisions for multiple LGS to cope

Using a near-infrared stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the CaII triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting functions for recently defined line-strength indices, namely CaT*, CaT and PaT, are provided. These functions can