In its most general acceptation, surface photometry is a technique applicable to any "extended" object, irrespective of the spectral band of the observational frame. The subject of this paper is restricted to the mapping of galaxies in the "standard" bands of the visible. By combining CCD images with deep large-field photographs, this technique

The influence of rotation and finite size of the radiation source on the orbits of dust particles around stars is analyzed. It is found that there are physical situations in which the results first derived by Robertson (Poynting-Robertson effect), corresponding to a nonrotating point-like source, cannot properly describe the dynamical behavior of

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The net circular polarization observed in solar faculae (Stenflo et al., 1984) follows a law expected from the combination of velocity and magnetic field gradients in the photosphere. To show this, the theoretical curve of growth (net circular polarization produced by a single line versus its absorption coefficient) predicted by this mechanism is

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