We present simultaneous spectropolarimetric observations of four visible (630 nm) and three infrared (1565 nm) spectral lines from the German Vacuum Tower Telescope, together with speckle-reconstructed filtergrams in the G-band and the Ca II H line core from the Dutch Open Telescope. After alignment of the data sets, we used the G-band intensity to

During its first data cycle, between 2005 and the beginning of 2006, the fast repositioning system of the MAGIC telescope allowed the observation of nine different gamma-ray bursts as possible sources of very high energy γ-rays. These observations were triggered by alerts from Swift, HETE-2, and INTEGRAL; they started as quickly as possible after

We present a new estimate of the lithium abundance in the atmosphere of the brown dwarf LP944-20. Our analysis is based on a self-consistent analysis of low-, intermediate- and high-resolution optical and near-infrared spectra. We obtain logN(Li) = 3.25 +/- 0.25 using fits of our synthetic spectra to the LiI resonance line doublet profiles observed

We present simultaneous high-resolution optical spectroscopy and X-ray data of the X-ray binary system GRMus (XB1254-690), obtained over a full range of orbital phases. The X-ray observations are used to re-establish the orbital ephemeris for this source. The optical data include the first spectroscopic detection of the donor star in this system

We analyze evolution of live disk-halo systems with gas fractions, fgas

Aims:We investigate the statistical properties of the extreme events of the solar cycle as measured by the sunspot number. Methods: The recent advances in the methodology of the theory of extreme values are applied to the maximal extremes of the time series of sunspots. We focus on the extreme events that exceed a carefully chosen threshold and a