Using MHD numerical experiments in three dimensions, we study the emergence of a bipolar magnetic region from the solar interior into a model corona containing a large-scale, horizontal magnetic field. An arch-shaped concentrated current sheet is formed at the interface between the rising magnetized plasma and the ambient coronal field. Three

Nowadays it is well established that BCDs are mostly old systems, as the vast majority of them have an extended low-surface brightness (LSB) stellar host underlying their central starburst component. This host generally extends several kpc from the star-forming (SF) regions, shows regular elliptical isophotes, and displays red colors indicative of

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Nuclear rings located within the central 1-2 kiloparsecs of barred spiral galaxies are often found to contain a large fraction of the total star formation taking place in a galaxy. Under the influence of a bar, gas can be channelled inwards along narrow ridges where shocks develop in the gas flow. We observe these shocks as dark dustlanes along the

Over recent decades there has been a proliferation of special-interest magazines dedicated to astronomy. In spite of the undoubted market for specialist feature articles on astronomy such articles appeal to a restricted sector of the general public and rarely appear in the daily or weekly press. I argue here that, apart from television documentary

We have compiled a new sample of 240 halo objects with accurate distance and radial velocity measurements, including globular clusters, satellite galaxies, field blue horizontal branch (FHB) stars and red giant stars from the Spaghetti survey. The new data lead to a significant increase in the number of known objects for Galactocentric radii beyond