Statistical techniques are devised to assess the likelihood of a Poisson sample of points in two and three dimensions, containing specific filamentary structures. For that purpose, Otto et al.'s (1986) expression for the probability density of clumps in a Poissonian distribution of points is generalized for any value of the density contrast. A way

CCD surface photometry of the radio galaxy B2 0034+25 is reported. Fourier analysis of the intensity variations along a set of closely spaced elliptical contours fitted to the intensity distribution reveals a high positive cos 4-theta component in the inner 10 arcsecs. Subtraction of elliptical models of the stellar light shows the presence of a

Not Available

IAUC 4740 available at Central Bureau for Astronomical Telegrams. IAUC 4740 available at Central Bureau for Astronomical Telegrams.

Photometric observations of a wide and a narrow outburst of the dwarf nova SS Cygni are used to test the hypothesis that the same mechanism is responsible for the wide outbursts of U Gem stars and the wide outbursts of SU UMa stars. A search for modulations at or near the orbital period of the SS Cygni outbursts was conducted, showing no

The bipolar outflow region S 106 is studied with optical spectroscopy and IR mapping techniques. The physical conditions in the ionized region, the density, temperature, ionic and total abundances of the primary atomic species, and the extinction trends and kinematic profiles, are analyzed. A model for the source is proposed in which primary