Quasars are considered to be the most luminous subclass among Active Galactic Nuclei. Although they appear to be distributed everywhere in the Universe, only a small fraction of them happen to be part of a fortuitous alignment with a galaxy or a galaxy cluster that lies along the line-of-sight, which results in multiple images of the background

We present a study of the spatial variation of forecast conditions at La Palma, Canary Islands. Previsions are obtained with the Weather Research and Forecasting (WRF) model in combination with the Trinquet-Vernin (TV) model, which allows us to compute the optical turbulence from the vertical gradient of the temperature and the wind velocity. The

We show that the morphology of the initial monolayers of InP on Al0.48In0.52As grown by metalorganic vapor-phase epitaxy does not follow the expected layer-by-layer growth mode of lattice-matched systems, but instead develops a number of low-dimensional structures, e.g., quantum dots and wires. We discuss how the macroscopically strain-free

We present high-spatial resolution spectropolarimetric observations of a quiescent hedgerow prominence taken in the He I 1083.0 nm triplet. The observation consisted of a time series in sit-and-stare mode of ~36 minutes duration. The spectrograph's slit crossed the prominence body and we recorded the time evolution of individual vertical threads

The VST Photometric Hα Survey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying the southern Milky Way in u, g, r, i and Hα at ˜1 arcsec angular resolution. Its footprint spans the Galactic latitude range -5o b +5° at all longitudes south of the celestial equator. Extensions around the Galactic Centre to Galactic latitudes ±10° bring

Context. The commonly used extinction laws of Cardelli et al. (1989, ApJ, 345, 245) have limitations that, among other issues, hamper the determination of the effective temperatures of O and early B stars from optical and near-infrared (NIR) photometry. Aims: We aim to develop a new family of extinction laws for 30 Doradus, check their general