Star formation rates (SFRs) larger than 1000 M&sun; yr-1 are observed in extreme starbursts. This leads to the formation of star clusters with masses >106 M&sun; in which crowding of the pre-stellar cores may lead to a change of the stellar initial mass function (IMF). Indeed, the large mass-to-light ratios of ultracompact dwarf galaxies and recent

Due to the continuous developments in polarimetric instrumentation, which will become even more dramatic in the near future with the availability of new generation solar telescopes, we are now severely confronted with a variety of new detailed observations of high diagnostic potential, whose interpretation requires a firmly established theoretical

We present new results from a ground-based program to determine the proper motion of the Magellanic Clouds (MCs) relative to background quasars (QSOs), being carried out with the Iréneé du Pont 2.5 m telescope at Las Campanas Observatory, Chile. The data were secured over a time base of seven years and with eight epochs of observation "As measured"

EST, the European Solar Telescope, is a 4-m class solar telescope, which will be located at the Canary Islands. It is currently in the conceptual design phase as a European funded project. In order to fulfill the stringent requirements for polarimetric sensitivity and accuracy, the polarimetry has been included in the design work from the very

This work reviews our understanding of the magnetic fields observed in the quiet Sun. The subject has undergone a major change during the last decade (quiet revolution), and it will remain changing since the techniques of diagnostic employed so far are known to be severely biased. Keeping these caveats in mind, our work covers the main

We report on the analysis of all 65 pointed Rossi X-ray Timing Explorer (RXTE) observations of the recently discovered soft X-ray transient MAXI J1659-152 (initially referred to as GRB 100925A). The source was studied in terms of its evolution through the hardness-intensity diagram (HID), as well as its X-ray variability properties. MAXI J1659-152