We present the most extensive combined photometric and spectroscopic study to date of the enormous globular cluster (GC) system around M87, the central giant elliptical galaxy in the nearby Virgo Cluster. Using observations from DEIMOS and the Low Resolution Imaging Spectrometer at Keck, and Hectospec on the Multiple Mirror Telescope, we derive new

In this paper we review some recent detections of wide binary brown dwarf systems and discuss them in the context of the multiplicity properties of very low-mass stars and brown dwarfs.

The black hole binary, Cyg X-1, is generally observed in one of two long duration X-ray states: a low flux, hard spectrum state (most common) and a high flux, soft spectrum state (rare). Models predict that the high/ soft state corresponds to a high mass transfer phase in the binary, and since the X-ray source is fueled by accretion from the

General properties of Luminous Blue Variables (LBV) have been reviewed by Lamers (1987). The LBV's are all close to the Humphreys-Davidson luminosity upper limit. The semi periods of the photometric microvariations with Delta V is about 0.1m are about twice as large as for normal supergiants of the same L and Teff, and 4-20 times larger than the

Here we present a self-consistent stationary solution for spherically symmetric winds driven by massive star clusters under the impact of radiative cooling. We demonstrate that cooling may modify drastically the distribution of temperature if the rate of injected energy approaches a critical value and that the stationary wind solution does not

A large fraction of all stars, after experiencing heavy winds at the end of the Asymptotic Giant Branch (AGB) phase, leave behind a core that is below the Chandrasekhar mass limit. This core eventually photoionizes the stellar ejecta giving birth to a planetary nebula (PN). PN and AGB stars are therefore the remnants of stars that through their