We present observations and 3D gasdynamic simulations of the jet and knots of the K 4-47 planetary nebula (PN) with the purpose of comparing the observed and predicted physical parameters. From the observations we obtain physical properties of different regions of the K 4-47 PN. We conclude that knots (K1 and K2) are produced by shocks while the

As part of a detailed study of the gas content in a sample of early-type galaxies, we present 21 cm H I line maps of the S0 galaxy NGC 404 at a spatial resolution of 15.2"'×14.4" (α×δ) and a velocity resolution of 2.6 km s-1. The H I has been traced out to a radius R~8R25 or 48 disk scale lengths, making it one of the largest H I extents reported

We have obtained deep near-infrared Ks-band William Herschel Telescope observations of a sample of 15 nearby spiral galaxies having a range of Hubble types and apparent bar strengths. The near-infrared light distributions are converted into gravitational potentials, and the maximum relative gravitational torques due to the bars and the spirals are

We present detailed spectroscopic analysis of nitrogen abundances in 31 unevolved metal-poor stars analysed by spectral synthesis of the near-UV NH band at 3360 Å observed at high resolution with various telescopes. We found that [N/Fe] scales with that of iron in the metallicity range -3.1

We measured the bar pattern speed in a sample of 7 SB0 galaxies using the Tremaine-Weinberg method. This represents the largest sample of galaxies for which the bar pattern speed has been measured this way. All the observed bars are as rapidly rotating as they can be. We compared this result with recent high-resolution N-body simulations of bars in

Large-Scale observing facilities are scarce and costly. Even so, the perspective to enlarge or to increase the number of these facilities are quite real and several projects are undertaking their first steps in this direction. These costly facilities require the cooperation of highly qualified institutions, able to undertake the project from the