In this paper we discuss the observational consequences of a dependence of meteor brightness on the entry angle z_R_, namely the decrease of the observed rates of meteors and the reduction of the population indices r for radiant zenith distances larger than zero. These effects, if not properly accounted for, lead to erroneous values of meteor

BROWN dwarfs are cool star-like objects that have insufficient mass to maintain stable nuclear fusion in their interiors. Although brown dwarfs are not stars, they are expected to form in the same way, and their frequency of occurrence should reflect the trends seen in the birthrates of low-mass stars. But finding brown dwarfs has proved to be

CLUSTERS of galaxies are the largest gravitationally bound systems in the Universe and therefore provide important constraints on the formation and evolution of large-scale structure. Cluster evolution can be inferred from observations of the X-ray emission of the gas in distant clusters, but interpreting these data is not straightforward. In a

Using a 2D generalization of Kent's model-independent decomposition method, we extract the K-band light profiles of the bulges of a sample of field galaxies with morphological types ranging from S0 to Sbc. We then examine the shape of the bulge profiles, by means of fitting a seeing-convolved power law of the form μ(r) is proportional to r^1/n^

We present intermediate resolution spectroscopy of the dwarf nova CY UMa in quiescence. From the radial velocities of the Hα emission, we derive an orbital period of 0.067 95+/-8x10^-5 d, which disagrees with previous photometric estimates. We also constrain the system parameters. The core of the Hα emission seems to be dominated by a component

T Tauri, the prototype of a class of low-mass pre-main sequence stars, was observed with the 3.6m Canada-France-Hawaii telescope (CFHT) and the CP40 photon-counting camera in November 1989. The data have been analysed using techniques of Speckle Interferometry to obtain diffraction-limited information on the spatial extent of T Tauri in narrow