The development of adaptive optics systems for projects related to large telescopes demands a proper knowledge of the atmospheric turbulence. Due to the lack of long-term information on optical turbulence, high-altitude winds (in particular winds at the 200-mbar pressure level) were adopted as a parameter for estimating the total turbulence at a

In planar symmetry (one-dimensional peculiar motions), using the Eulerian perturbative framework and an arbitrary initial profile, we compute the analytical evolution of the peculiar velocity and the density contrast up to the fourth order (E1-E4 approximations). From these results and the exact (Lagrangian) solutions, the accuracy of the Ej (j

EURONEAR - The European Near Earth Asteroid Research is a project initiated recently by a small team presently based in France, Romania, and South Africa. It envisions to build a coordinated network which will follow-up and recover Potentially Hazardous Asteroids (PHAs) and Near Earth Asteroids (NEAs), using time available at 1m class telescopes in

The relation between the Evershed flow and moving magnetic features (MMFs) is studied using high-cadence, simultaneous spectropolarimetric measurements of a sunspot in visible (630.2 nm) and near-infrared (1565 nm) lines. Doppler velocities, magnetograms, and total linear polarization maps are calculated from the observed Stokes profiles. We follow

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THE active nuclei of Seyfert 1 galaxies are characterized by a small (˜0.03 pc) region of intense broad emission lines, indicative of gas moving at extremely high velocities and ionized by a non-thermal radiation field. These spectral features are usually explained by invoking the presence of a central supermassive black hole. Here we present two