Although the h and k lines of Mg II are expected to be of great interest for probing the upper solar chromosphere, relatively little is known about their polarization properties which encode the information on the magnetic field. Here we report the first results of an investigation whose main goal is to understand the physical mechanisms that

We identify an inner-belt, low-inclination origin for 1999JU3 through the Nu6 resonance. Within this region there are three possible sources, the Erigone and Polana families, and a background population of low-albedo and low-inclination asteroids.

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We report on UV and X-ray spectroscopy and broadband optical observations of the ultraluminous X-ray source in Holmberg II. Fitting various stellar spectral models to the combined, non-simultaneous data set, we find that normal metallicity stellar spectra are ruled out by the data, while low-metallicity, Z = 0.1 Z &sun;, late O-star spectra provide

Here we present our determination of the black hole - mass function for spiral galaxies in our local universe. We have established our black hole - mass function from a volume-limited sample, consisting of a statistically complete collection of the brightest spiral galaxies in the Southern (δ 0°) hemisphere. The volume-limited sample is defined by

The Ly α lines of H I and He II are two of the spectral lines of choice for FUV and EUV channels of narrowband imagers on board sounding rockets and space telescopes, which provide spectacular intensity images of the outer solar atmosphere. Since the magnetic field information is encoded in the polarization of the spectral line radiation, it is