We present accurate optical surface photometry in the U, B, V, R, and I passbands for 11 disk galaxies. The sample has been selected in order to study the different morphological structures present in disk galaxies and includes all morphological types. For each galaxy, we present surface brightness, ellipticity, and position angle radial profiles

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We overview the different classes of B-type pulsators and show from our ground-based data that current data sets are insufficient to derive the complete frequency spectrum. From line-profile studies, we find that many modes with small amplitudes are excited in some stars, of which extensive ground-based photometry has revealed only one frequency

A method based on Lucy's iterative algorithm is developed to invert the equation of stellar statistics for the Galactic bulge and is then applied to the K-band star counts from the Two-Micron Galactic Survey in a number of off-plane regions (10 deg>|b|>2 deg, |l|

OB associations and young open clusters constitute the most prolific nucleosynthesis sites in our Galaxy. The combined activity of stellar winds and core-collapse supernovae ejects significant amounts of freshly synthesised nuclei into the interstellar medium. Radioactive isotopes, such as 26Al or 60Fe, that have been co-produced in such events may