Oxygen abundances have been derived in a sample of very metal-poor stars from observations of the Oi triplet at /λλ 7771-5 Å and OH lines in the near UV. Iron abundances derived in LTE were corrected for NLTE effects following Thévenin and Idiart [ApJ 521 (1999) 753]. Furthermore, a detailed NLTE analysis of iron lines has been carried out for one

OSIRIS (Optical System for Imaging and low/intermediate-Resolution Integrated Spectroscopy) will be one of the Day One instruments for the Spanish 10.4m telescope GTC at La Palma. One of the scientific projects to be addressed with OSIRIS is the study of the galaxy population in clusters of galaxies at high redshift. Part of the cluster sample

We report complete near-infrared (0.9-2.4 mu m) spectral observations of trans-neptunian objects (TNOs) 2000 EB173 and 2000 WR106 collected using the new Near Infrared Camera Spectrometer (NICS) attached to the 3.56 m Telescopio Nazionale Galileo (TNG). Both spectra are very red and with a quite strong and broad drop extending throughout the K band

We present high resolution (15'' and 2.5 km/s) HI observations of the S0 gal axy NGC 404. We derive an HI mass of MHI = 6.7 × 107 Msolar, in good agreement with previous measurements. The HI is distributed in a broad annulus and extends out to a diameter of 9', well beyond the optical diameter of 6'. The velocity field is regular and shows

We present the properties of all the galaxies detected by ISO at 7, 15 and 90 microns in ELAIS northern fields. The spectral energy distribution (SED) of those 20 galaxies with IRAS detections can generally be well fitted by a predominant cirrus component plus a modest starburst contribution. Follow-up spectroscopy has shown that all the objects

Cuando la envoltura de una estrella en la rama asintontica de gigantes (RAG) es eyectada e inonizada por el nucleo estelar se produce la formacion de las nebulosas planetarias (NPs). La NPs representan un entorno inigualable para el estudio de procesos fisicos fundamentales como la evolucion estelar y la evolucion quimica del medio interestelar (MI