We investigate the kinematic and magnetic properties of G-band bright points in the moat of a regular sunspot. The analysis is based on vector polarimetric measurements made at the German Vacuum Tower Telescope in visible (630 nm) and infrared (1565 nm) spectral lines, complemented by high-resolution filtergrams in the G-band at 430.6 nm and the

Mid-resolution spectra are used to deduce the size and kinematics of the coronal region in a sample of Seyfert galaxies by means of observations of the [Fe XI], [Fe X], [Fe VII], [Si VI], and [Si VII] lines. These coronal lines (CLs) extend from the unresolved nucleus up to a few tens to a few hundreds of parsecs. The region of the highest ionized

We present the results of the analysis of temporal series of spectro-polarimetric data measured simultaneously in the photospheric Si I 10827 Å line and the chromospheric He I 10830 Å triplet, on top of two different targets: a facular region and the umbra of a sunspot. The full Stokes inversion of both spectral features gives us the temporal

Aims.With strong evidence of fast and slow magnetoacoustic modes arising in the solar atmosphere there is scope for improved determinations of coronal parameters through coronal seismology. Of particular interest is the ratio P1/2P2 between the period P1 of the fundamental mode and the period P2 of its first harmonic; in an homogeneous medium this

The results of the determination of magnetic field strength and flux from weak polarimetric signals in solar inter-network regions are contradictory. We investigate the origin of this contradiction with the help of MHD simulations. It is shown that the Stokes-V line ratio of the Fe I 5247/5250 Å and 15652/15648 Å line pairs is a good indicator of

Results of photometric surveys have brought to light the existence of a population of giant planets orbiting their host stars even closer than the hot Jupiters (HJ), with orbital periods below 3 days. The reason why radial velocity surveys were not able to detect these very-hot Jupiters (VHJ) is under discussion. A possible explanation is that