A description is given of the activities of an international working group created with the aim of obtaining both photometric and astrometric observations of visual double and multiple stars with angular separations in the range of one to fifteen arcseconds, that formed part of the HIPPARCOS Input Catalogue. The scientific aims and realisations of

New calculations of the Galactic contamination over microwave background radiation anisotropies are carried out. On the one hand, when a frequency-dependent contrast of molecular clouds with respect to the Galactic background of the diffuse interstellar medium is taken into account, the anisotropic amplitude produced by Galactic dust is increased

IAUC 7161 available at Central Bureau for Astronomical Telegrams.

The HST snapshot survey of 108 BL Lac objects has revealed several instances of unusual morphologies, three jets and a possible Einstein ring. Of the three detected optical jets, two were already known (PKS 0521-365 and 3C371) and one is a new discovery (PKS 2201+044). At HST resolution the jets are well resolved and individual knots clearly seen

We find the distribution of coalescence times, birth rates, spatial velocities, and subsequent radial offsets of coalescing neutron stars (NSs) in various galactic potentials accounting for large asymmetric kicks introduced during a supernova. The birth rates of bound NS-NS binaries are quite sensitive to the magnitude of the kick velocities but

We describe the Long Wavelength Array (LWA), a ground-based radio interferometer capable of serving as a coronal mass ejection (CME) detector. Previous low-frequency (nu 50 MHz) coronal sounding experiments have shown that CMEs exhibit large radar cross sections. The LWA will serve as the imaging receiver for a bi-static radar observatory that