We report on sensitive high-resolution surveys of the central part of the Andromeda galaxy (M31) with Chandra at X-ray wavelengths and with the Very Large Array at radio wavelengths -- 4.9 and 8.4 GHz. The combination of the data has revealed a number of coincident sources of which two new extended X-ray/radio supernova remnants. Also, the presumed

Quiet Sun magnetic fields in the internetwork are almost ubiquitous. Simultaneous observations in infra-red and visible lines and high spatial resolution ( 0.5'') data in visible lines show that their field strengths range from below few hundred Gauss to kilo-Gauss. Most of the flux is contained in small-scale, strong-field features located mainly

HR1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with a frequency spectrum of alternating even- and odd-l modes that are distorted by the presence of a strong, global magnetic field. Several recent theoretical studies have found that within the observable atmospheres of roAp stars the pulsation modes are magneto-acoustic with

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