We report on long-term multiwavelength monitoring of blazar Mrk 421 by the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration and Steward Observatory, and by the Swift and Fermi satellites. We study the source behaviour in the period 2007-2015, characterized by several extreme flares. The ratio between the

On the basis of a new photometric analysis of the Local Group dwarf irregular galaxy NCG 6822 based on observations obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope, we have obtained a new estimate of the extinction of two fields located in the southeast region of the galaxy. Because of significant differences in the

In order to develop a reliable method of distance determination of W UMa-type stars, a catalogue of light curve solutions of 159 systems has been compiled. The rate of transferred luminosity from the primary star to the secondary star was determined based on the catalogue data. This quantity has an important role in the distance determination. The

Division II provides a forum for astronomers studying a wide range of problems related to the structure, radiation and activity of the Sun, and its interaction with the Earth and the rest of the solar system.

In a recent book, Dodson (2009) has presented an updated impression of the Amarna period, in heavy contrast to the one lately defended by Krauss (2008) and other authors such as Reeves (2002) or Gabolde (2005), where Dodson uses the recent archaeological and epigraphical sources to offer an state of the art version of this fascinating historical

A good alternative to traditional methods of passing on astronomical concepts is to use a 'collateral' story that catches the public's attention. It may also simultaneously give a vital opportunity to awaken the critical faculty that often seems so perilously close to extinction these days. The recipe is simple: nothing but an actor or actress, his