Strong light bridges (SLBs) represent an abrupt change in the physical conditions of sunspot umbrae. They divide the umbra into separate units (fragments, umbral cores) and very often show a granular structure. A photometric and spectroscopic study of SLBs, and also of abnormal granulation (AG) in a region of pores, is presented. Slit-jaw images

We have observed the linear polarization of 21 bright grains of the photospheric network close to the disk center. The linear polarization of Fe I 6302.5 A was always lower than 1.9 x 10-3 (referred to continuum intensity). This level of linear polarization implies a very small magnetic field inclination with respect to the vertical, which we

We present the results on the optical morphology and structure of 25 low-luminosity radio galaxies. The radial dependence of parameters like the surface brightness, ellipticity, center, and position angle of the isophotes is presented to study the properties of the galaxies. Results for individual objects are discussed.

IAUC 5968 available at Central Bureau for Astronomical Telegrams.

The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which complement the data set formed by the International Ultraviolet Explorer (IUE) spectra, discussed elsewhere. Spectroscopic and

We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant