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An objective prism H alpha survey has shown that there is a population of early type spiral galaxies in nearby clusters with strong central bursts of star formation which could be due to galaxy--galaxy tidal interactions. Such galaxies are rarely found in the field.

A survey of chemical abundances and radial velocities for a spatially selected sample of RR Lyrae stars has been started. Assuming an absolute magnitude of -0.6 for these objects, this leads to a near spherical volume of 2 kpc radius to be explored. Special emphasis is devoted to those RR Lyrae stars contained in the Input Catalogue of the

Light curves of the 12 μm emission following the collision of Shoemaker-Levy 9 fragments A, E, H, L, Q1 with Jupiter are presented. Impacts F, P2, Q2, T, U were monitored, but not detected. The observations were carried out with the Saclay CAMIRAS camera mounted on the 2.56 m Nordic Optical Telescope located at La Palma (Canary Island, Spain). Of

We present narrowband H-alpha imaging and long-slit optical and near-infrared spectroscopy of the giant H II region NGC 2363. The spectroscopic data are taken at two positions, in the brightest core and in a knot approximately 6 sec to the east, where we have found broad emission lines at 4660 A and 5810 A attributed to WC stars which suggest an