Sabemos que hay varios procesos dinámicos en la Galaxia que pueden ser explicados con acreción de gas al disco Galáctico. Por ello hemos decidido investigar concretamente a las nubes de alta velocidad, o HVCs. Al estudiar al Complejo H, una nube en nuestra propia Galaxia que parece estar interaccionando con el disco Galáctico, encontramos que la

Context: Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). Aims: We derived the mechanical wave energy as seen in line-core velocities on disc centre to obtain a measure of mechanical energy flux with height for a comparison with the energy

We present an abundance analysis of the star Cernis 52 in whose spectrum we recently reported the naphthalene cation in absorption at 6707.4 Å. This star is on a line of sight to the Perseus molecular complex. The analysis of high-resolution spectra using a χ2-minimization procedure and a grid of synthetic spectra provides the stellar parameters

Aims: Following the study presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 ≤ z ≤ 0.25 imaged in the central 0.5-2 Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population Methods: We

Intermediate-resolution (0.5-1 Å) optical spectroscopy of the cataclysmic variable (CV) SY Cnc reveals the spectrum of the donor star. Our data enable us to resolve the orbital motion of the donor and provide a new orbital solution, binary mass ratio and spectral classification. We find that the donor star has spectral-type G8 +/- 2 V and orbits

Aims: We suggest an explanation for the high-frequency power excess surrounding active regions known as seismic halos. Methods: We use numerical simulations of magneto-acoustic wave propagation in a magnetostatic sunspot model. Results: We propose that seismic halos can be caused by the additional energy injected by high-frequency fast mode waves