The authors present preliminary results of a CCD survey of nearby (z 0.1) northern galaxies which have well defined radio jets. The main objectives are to: (1) detect - or put constraints to - the presence of optical jets in these galaxies, (2) obtain high dynamic range maps of known optical jets, and (3) make a detailed comparison of the results

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Extensive monitoring is now available for a good sample of the brighter quasars and BL Lacs. In some cases, lightcurves are well enough sampled to permit stochastic modelling. The authors present here, a simple model of the lightcurve of the prototype BL Lacertae object, BL Lac in terms of a series of random events, each with rapid rise and

With an adequate supply of matter, the inward drifting of dust particles induced by the Poynting-Robertson effect can lead to the formation of a shell or disk-like structure around the source of radiation. In a steady state, the Poynting-Robertson effect produces a spatial density of dust in the form of 1/r which in turn gives rise to a mid