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The CFHT image stabilizing camera HRCam was used to search for closely spaced images indicative of gravitational lensing among a sample of 101 apparently and intrinsically luminous quasars. No conclusive evidence of multiple imaging due to lensing was found. Although these results are in accord with recent predictions based on standard models of the universe. Turner (1990, ApJ, 365) points out that model universes dominated by a nonzero cosmological constant are not favored. No significant excess of galaxies near the quasars was found, in contrast to the results of Webster et al. (1988, Nature,336), and, more recently, by Drinkwater et al. (1991, ASP Conf. Ser., 21)

High dispersion ultrahigh signal to noise Reticon spectra of Vega were obtained with the coude spectrograph of the 1.2 m telescope. A mean signal to noise ratio of 2500 over the spectral region lambdas from 3825 to 5435 was achieved. Examination of the line profiles confirmed the presence of two different types of profiles which were previously seen in IIIaJ and lower signal to noise Reticon spectra. The profiles of the strong lines are essentially classical rotational profiles with enhanced wings which are slightly stronger than expected while those of weak lines are clearly flat-bottomed resulting in a trapezoidal appearance. A few possible theoretical explanations are presented.

This paper presents CCD photometry for the gravitationally lensed quasar system 2237 + 0305, in optical passbands from B through R, taken over a time period of more than 3 yr. These data provide new information about the probable microlensing event reported by Irwin et al. (1989); the rise time of this feature is approximately 26 days. Four additional independent brightness changes in the quasar images are detected.

We present radial-velocity spectrometer observations that indicate that Ba II stars are binary systems. The secondary stars of these systems have low masses, consistent with their being degenerate objects which have lost mass onto their primaries in a previous stage of evolution. It is suggested that the Population II equivalents, the CH stars, may also be binary systems. This may be related to the fact that they are found only in globular clusters of the lowest central concentration.

We have obtained radial velocities for 69 stars in the globular cluster M2 (NGC 7089). M2's rotation axis is, within sizeable uncertainties, perpendicular to the major axis determined by the flattening. The ratio of rotational to random kinetic energy agrees with that predicted from the ellipticity assuming an oblate figure and an isotropic velocity-dispersion tensor. We have fitted King-Michie models to determine M2's mass, the exponent of an assumed power-law mass function, and the anisotropy radius. The most significant sources of uncertainty in the modeling are the velocity dispersion, the distance, and the mass-luminosity relation for the cluster stars. The models favor mass functions similar to or shallower than the Salpeter initial-mass function and a moderate amount of velocity anisotropy.

Radial velocities accurate to about 1 km/s have been obtained for about 20 stars in each of the two cusp clusters NGC 6624 and M70 and in the centrally concentrated noncusped cluster M28. NGC 6624 and M70 are equally well fit by single and multicomponent King (1966) models with concentrations of greater than 2.0, and M28 is best fit by models with a concentration near 2.0. It is found that the M/L ratios of NGC 6624, M28, and M70 do not differ significantly from each other or from those of the cluster population as a whole, and that anisotropic models are poorer fits to the surface-brightness profiles than isotropic models. M28 and M70 are found to have less than about 25 percent of their mass in the form of remnants heavier than the giants, while NGC 6624 has less than about 10 percent in this form. 68 refs.