The nature of the dark bursts is still not fully understood. Here, we report on some of our recent studies on Swift dark bursts. Thereby, we pay particular attention to GRB 050717, for which we obtained a deep imaging of the X-ray error circle with the newly commissioned GROND camera mounted at the 2.2 m telescope on La Silla.

We present results on the oscillatory properties (periods, damping rates, and spatial distribution of perturbations) for resonantly damped oscillations in a system of two inhomogeneous coronal slabs and compare them to the properties found in single slab loop models. A system of two identical coronal loops is modelled, in Cartesian geometry, as

Aims: The BL Lac object RGB 1745+398 lies in an environment that makes it possible to study the cluster around it more deeply than the environments of other BL Lac objects. The cluster centered on the BL Lac works as a strong gravitational lens, forming a large arc around itself. The aim of this paper is to study the environment and characteristics

The influence on the fusion process of coupling transfer/breakup channels is investigated for the medium weight 6,7Li+59Co systems in the vicinity of the Coulomb barrier. Coupling effects are discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model. Applications to 6He+59Co induced by the borromean halo

Following recent abundance measurements of Mg, Al, Ca, Fe, and Ni in the black hole X-ray binary XTE J1118+480 using medium-resolution Keck II ESI spectra of the secondary star, we perform a detailed abundance analysis including the abundances of Si and Ti. These element abundances, which are higher than solar, indicate that the black hole in this

Oceanic Anoxic Event 1a (OAE1a) is now generally recognized to correlate with the lower part of the Leupoldina cabri planktonic foraminifer Zone. Unfortunately, the calibration of this zone against the standard ammonite scale has remained uncertain. Our recent high-resolution geochemical study (Carbon-isotope) of Lower Aptian sequences in the