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

To investigate the distribution of dust in Sb and Sc galaxies we have analyzed near-infrared and optical surface photometry for an unbiased sample of 37 galaxies. Since light in the K-band is very little affected by extinction by dust, the B - K colour is a good indicator of the amount of extinction, and using the colour-inclination relation we can