Aims: Within the framework of site qualification for the future European large telescope E-ELT, a campaign of measurements was carried out for ten nights in December 2007 at Paranal using six independent instruments. Methods: To characterize the optical turbulence, two techniques were used: the statistical analysis of the fluctuations of the angle

Context: .GRB 050730 is a long duration high-redshift burst (z=3.967) that was discovered by Swift. The afterglow shows variability and was well monitored over a wide wavelength range. We present comprehensive temporal and spectral analysis of the afterglow of GRB 050730 including observations covering the wavelength range from the millimeter to X

V1647 Ori is a young eruptive variable star, illuminating a reflection nebula (McNeil's Nebula). It underwent an outburst in 2003 before fading back to its pre-outburst brightness in 2006. In 2008, V1647 Ori underwent a new outburst. The observed properties of the 2003-2006 event are different in several respects from both the EXor and FUor type

The OJ-94 international collaboration has been observing the light curve of OJ287 intensely at radio, millimetric, infrared and visible wavelengths. We present a set of light curves for the 1993/94 observing season in 14 different bands from 4.8GHz to U. The monitoring covers an interval from August 1993 to the end of June 1994. The intensity of

We present high-time-resolution multicolour observations of the quiescent soft X-ray transient V404 Cyg obtained with ULTRACAM. Superimposed on the ellipsoidal modulation of the secondary star are large flares on time-scales of a few hours, as well as several distinct rapid flares on time-scales of tens of minutes. The rapid flares, most of which

We combine a number of powerful mathematical techniques to produce an effective method for treating multidimensional radiative transfer problems in complex atomic models without assuming local thermodynamic equilibrium (LTE). The approach is so efficient that multilevel two-dimensional (2D) modeling can now be performed with no more than a