Small-scale fluctuations of magnetic field and velocity may be responsible for the Stokes asymmetries observed in all photospheric magnetic structures (the microstructured magnetic atmosphere [MISMA] hypothesis). We support the hypothesis by showing that atmospheres with optically thin microstructure reproduce the polarization of Fe I λλ6301.5 and

We have derived the photometric parameters for the structural components of a sample of fourteen SB0 galaxies by applying a parametric photometric decomposition to their observed I-band surface brightness distribution. We find that SB0 bulges are similar to bulges of the early-type unbarred spirals, i.e. they have nearly exponential surface

We continue the presentation of the results of detailed spectroscopic and photometric study of Shakhbazian compact galaxy groups. They belong to the interesting class of compact groups. Because of their large number (the catalogue contains 377 entries) we are able to study the groups in different stages of evolution. Here we give the results of a

We have carried out a detailed spectral analysis of six early B-type supergiants in the Sculptor Group spiral galaxy NGC 300. To this end, we used state-of-the-art unified blanketed non-local thermodynamic equilibrium model atmospheres (computed with the code FASTWIND), aimed at the determination of the stellar parameters and of detailed surface

We present three different optical and near-infrared (NIR) data sets for evolved stars in the Galactic globular cluster ω Centauri. The comparison between observations and homogeneous sets of stellar isochrones and zero-age horizontal branches provides two reasonable fits. Both of them suggest that the so-called anomalous branch has a metal

We report novel spectropolarimetric observations of sunspots carried out with the Tenerife Infrared Polarimeter in a near-IR spectral region around 15410 Å, which is known to contain two groups of prominent OH lines that show circular polarization signals of opposite polarity. Surrounding these well-known OH lines, we have discovered the presence