A a part of a general chromospheric modelling programme on late-type dwarfs, the authors searched for the spectroscopic variability in chromospheric lines...

Context. The two Oe stars HD 45 314 and HD 60 848 have recently been found to exhibit very different X-ray properties: whilst HD 60 848 has an X-ray spectrum...

We present stellar parameters and metallicities, obtained from a detailed spectroscopic analysis, for a large sample of 98 stars known to be orbited by...

Aims: We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray burst GRB 040924. This GRB had a rather short duration of T90...

Context. We present new spectroscopic and polarimetric observations of the gravitational lens SDSS J1004+4112 taken with the 6 m telescope of the Special...

We present high and low resolution multi-slit spectroscopy, together with V, forbidden O III, and H-alpha narrow band imaging of the unusual bipolar outflow...

Aims: We present constraints on the thermodynamical structure of the chromosphere from ground-based observations of the Ca ii H line profile near and off the...

Spicules of the so-called type II were suggested to be relevant for coronal heating because of their ubiquity on the solar surface and their eventual extension...

We explore whether medium-resolution stellar spectra can be reconstructed from photometric observations, taking advantage of the highly compressible nature of...