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A study has been undertaken of the physical conditions of the ionized gas within the starburst region of the galaxy NGC 253, using long slit spectroscopy at high spatial and spectral resolution. The aim was to identify the appropriate parameters describing the dynamics of the gas and the excitation conditions, in relation with the starburst process

High-resolution maps of the spiral galaxies NGC 3992 and NGC 4321, obtained with the Taurus camera at the 4.2-m William Herschel Telescope are analyzed. The results obtained include (1) the total number of separately identifiable H II regions in their disks (classified according to their membership of a spiral arm or the interarm disk, (2) the

A two-week time series of precise radial velocity measurements of Alpha Bootis (Arcturus) covering 7-8 hr per night is reported. The radial barycentric velocity of the star is found to be -5021 + or - 5 m/s. When data from the whole run are jointly analyzed, several equispaced peaks in the frequency appear in the range of a few microhertz, the

A new method has recently been developed to obtain the Fried's parameter from observations of granulation outside the disk center, based on the different degradation suffered by the images on the directions parallel and perpendicular to the solar limb, due to the geometrical foreshortening. This procedure has been applied to CCD images obtained at

Spectroscopic observations, with high spatial resolution, of Ca II K bright points very near the disk center are presented. Magnetic concentrations have been detected in these network (facular) points by only using intensity profiles of the well-known pair of lines Fe I 5250.22 A and 5247.06 A. No brightening of these structures with respect to the