Large HI shells, with diameter of hundreds of pc and expanding with velocities of order 10-20 kms^-1 have been detected in their hundreds in the Milky Way and are well observed features of local gas rich galaxies. These shells could well be predicted as a result of the impact of OB associations on the ISM, but doubt has been cast on this scenario

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We present the results of a dynamical analysis of the radio-halo cluster A2744 based on optical data. We find that this cluster is in an advanced merging phase, with two galaxy subsystems impacting along a direction close to the line- of-sight, likely observed just after the core passage.

The determination of the extinction in different directions in the Galaxy and in external galaxies is of paramount importance in several fields of astrophysics. The determination of the extinction law provides clues to the nature of the Inter/Circum-Stellar Medium (ISM/CSM), specifically to that of the dust particles. Recent studies have shown that

The successful launch of the CoRoT (COnvection, ROtation and planetary Transits) satellite opens a new era in asteroseismology. The space photometry is complemented by high-resolution spectroscopy and multicolour photometry from ground, to disclose the pulsational content of the asteroseismic targets in the most complete way. Some preliminary