We present a Monte Carlo model to compute cometary dust tail brightnesses. The model, anologous in many ways to that developed by Fulle (1989, Astron. Astrophys. 217, 283), computes the keplerian orbit of each grain released from the nucleus surface in the Sun gravity field reduced by the radiation pressure. It can be used to derive the time

The quantification of the solar magnetic field is a crucial step in modern solar physics to understand the dynamics, activity and variability of our star. Presently, a reliable inference of these fields is only possible by means of a computer-intensive process that has so far limited scientists to the analysis of observations from small regions of

A survey of interstellar Na I D1 and D2 absorption features in the spectra of 104 early-type stars in the second and third Galactic quadrants reveals the large-scale kinematics of the interstellar gas within the Galactic anticenter hemisphere at distances from the Sun between ~70 and ~250 pc. Employing a technique that uses both the radial

We present ample evidence for the presence of continuing gaseous infall to the Galactic plane, and then show how interaction of this gas with the disc gas yields a warp of the observed amplitude and direction. The mechanism works for galaxies in general, predicting a small proportion of U-shaped warps, as observed.

This book covers normal galaxies, distant galaxies, studies based on far-infrared diagnostics, quasar absorption lines, and the properties of nearby galaxies. The timely volume provides an essential reference for astronomers working in the field of high-redshift galaxies. It includes the lectures delivered at the XI Canary Islands Winter School of

We present a compilation of high time-resolution photometric observations of quiescent soft X-ray transients obtained with the Acquisition Camera on Gemini-South. A0620-00 (V616 Mon) was observed with a short cycle time and high precision. Superimposed on the ellipsoidal modulation we find several prominent flares together with weaker continual