The bulk of the quiet solar photosphere is thought to be significantly magnetized, due to the ubiquitous presence of a tangled magnetic field at subresolution scales with an average strength langBrang ~ 100 G. This conclusion was reached through detailed three-dimensional (3D) radiative transfer modeling of the Hanle effect in the Sr I 4607 Å line

We present wide-field photometry of resolved stars in the nearby Sculptor dwarf spheroidal galaxy using CTIO/MOSAIC, going down to the oldest main sequence turn-off. The accurately flux calibrated wide field colour-magnitude diagrams can be used to constrain the ages of different stellar populations, and also their spatial distribution. The

Using spectropolarimetric data of an Active Region (AR) filament we have carried out inversions in order to infer vector magnetic fields in the photosphere (Si I line) and in the chromosphere (He I line). Our filament lies above the polarity inversion line (PIL) situated close to disk center and presents strong Zeeman-like signatures in both

Following the report of renewed activity of the microquasar H1743-322 (aka IGR J17464-3213, ATels #3263, #3267) we have triggered a Swift ToO. The observation was performed on April 10, 2011 between 7.9h UT and 16.12h UT, therefore in quasi-simultaneity with the INTEGRAL bulge monitoring program (April 10, 2011 18.0h UT to 21.7h UT). The Swift/XRT

I summarize the tools of Bayesian theory for inference that are recently being applied to extract information from spectro-polarimetric data obtained with the most advanced instruments. I present the machinery to carry out inference, model comparison and model averaging, together with some illustrative examples, with the hope that the power of

The weak-field approximation is one of the simplest models that allows us to relate the observed polarization induced by the Zeeman effect with the magnetic field vector present on the plasma of interest. It is usually applied for diagnosing magnetic fields in the solar and stellar atmospheres. A fully Bayesian approach to the inference of magnetic