We present an analysis of the Hα emission line profiles of a sample of giant extragalactic HII regions, selected from among the brightest and most isolated in a group of spiral galaxies for which we have photometric and spectroscopic data: NGC 157, NGC 3631, NGC 6764, NGC 3344, NGC 4321, NGC 5364, NGC 5055, NGC 5985, NGC 7479. Our study confirms

Bellazzini et al. (2006b) claim that Lopez-Corredoira et al.'s (2002) warp model is totally unable to reproduce the Canis Major structure in the red clump stars. However, slight variations in the azimuth of the Lopez-Corredoira et al. (2002) warp model, justified by the uncertainties in the parameter as well as the local irregularities with respect

We investigate flux tube emergence in the solar photosphere using a diagnostic procedure based on analyzing Stokes signals from different spectral lines calculated in 3-D radiation-MHD simulations. The simulations include the effects of radiative transport and partial ionization and cover layers both above and below the solar surface. The

Detached eclipsing binaries (EBs) provide a unique opportunity to carry out stringent tests on stellar evolution models. The value of EBs is enhanced by their membership in open clusters, but the number of known systems is still very scarce. We have started a systematic search for late-type EBs in the nearest open clusters with the fully robotic

On behalf of the UKIDSS consortium, we present the first brown dwarfs found in the UKIRT Infrared Deep Sky Survey (UKIDSS). UKIDSS began in May 2005 and will survey 7500square degrees of the Northern sky, extending over both high and low Galactic latitudes, in JHK to K=18.3. This depth is three magnitudes deeper than 2MASS. UKIDSS searches for the

Aims.We discuss a simple model of a line-tied coronal arcade with piecewise constant density to explore the effects of curvature on radially polarised fast modes.Methods.A partial differential equation is derived for the velocity perturbation of the fast modes and it is solved analytically in terms of Bessel functions of half integer order