The secondary objective of the GOLF Experiment on-board the SOHO space mission is to measure the line-of-sight component of the disk averaged magnetic field of...

The intensity distribution of the penumbra at different stages of evolution has been analyzed. The results have been different for both evolved and primitive...

Only less than 150 Wolf-Rayet galaxies are actually known. Many of them are dwarf or irregular galaxies, and some show close companion objects. Peculiar...

NGC 7293, the Helix nebula, represents one of the rare instances in which theoretical predictions of stellar evolution can be accurately tested against...

Multiple shell planetary nebulae (MSPNe) are those which, in addition to the main bright inner shell, show one or two additional external shells. These faint...

Based on optical data we propose a dynamycal model for A115. From spatial and radial velocity distributions we find three massive subsclusters that configure a...

We analyse spectral images across the full emission line in H_α of the discs of M100 and M101, extracting for each HII region its spectrum, and for the more...

Recent integral-field spectroscopy observations have revealed that thick- and thin-disk star-formation histories are regulated by the interplay of internal and...