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

An observational test of the binary hypothesis for the origin of blue straggler stars is conducted by searching for radial velocity variables among 30 blue stragglers in several galactic clusters. Only one of the slowly rotating blue stragglers is detected as a radial velocity variable, and it is shown that this finding does not correspond to the

The physical parameters of Tau Cet are analyzed based on new and high-quality data. The effective temperature is determined to be 5250 + or - 50 K. The discrepancy of the abundance inferred from the Fe I lines with the lowest excitation cannot be explained by errors either in atomic or stellar parameters and implies the need for models