The study of extragalactic extinction laws is of paramount importance as it plays a key role in galaxy evolution, as well as for the determination of the cosmological parameters, for example using SNe. We propose to utilize a new technique based on flux measurements of gravitationally lensed, multiply-imaged QSOs to estimate the extinction law of

We have investigated the structural and dynamical properties of triaxial stellar systems whose surface brightness profiles follow the r1/n luminosity law - extending the analysis by Ciotti, who explored the properties of spherical r1/n systems. A new analytical expression that accurately reproduces the spatial (i.e., deprojected) luminosity density

We report the discovery of an unusual low-ionization broad absorption line quasar at z=1.776 which exhibits absorption lines from many excited states of Fe II. This member of the rare class of ``FeLoBAL'' quasars was serendipitously found in a mid-infrared (MIR) survey of distant clusters carried out with the ISOCAM camera. ISO J005645.1-273816 has

The photometric decay of sunspots is studied in some detail. Aspects related to leader vs. follower sunspot decay are presented and our current understanding of the physical mechanisms involved critically reviewed. The intrinsic instability of follower spots to form a stable sunspot cannot be understood in terms of the fluting stability as proposed

Integral field optical spectroscopy using the INTEGRAL system (complemented with Hubble Space Telescope WFPC2 imaging) is used to characterize the kinematic and ionization properties of the warm ionized gas in the ultraluminous infrared galaxy IRAS 15206+3342. These data present kinematic and morphological evidence for a tidal tail connecting the

We propose to measure the expansion parallax of the nebulae around the binary symbiotic Miras He 2-104 {the Southern Crab} and He 2-147 by means of high resolution WFPC2/F658N images to be taken at two different epochs. Given the large outward velocities of these nebulae inferred from ground-based spectroscopy, their apparent expansion can be