More than half of all stars in the Galaxy formed and evolved as binary systems and their study is essential for understanding stellar and galactic evolution. Six lectures in this book give both a readable introduction and an up-to-date review of nearly all aspects of current research into binary stars, including the range from common binaries to

Our spectral diagnostic based on the intensity of the [OI]λ6300Å line indicates that many observed HII regions are indeed density-bounded. The estimated fractions of escaping Lyman continuum photons range from 15 to even more than 50%.

Not Available

Not Available

We combine H_α and broad-band optical imaging and H_α velocity mapping over the face of the barred galaxy NGC 3359, obtained within the BARS programme on the Canary Island telescopes (Lourenso and Beckman, these proceedings). From the H_α image we have determined the positions, fluxes and diameters of a total of 547 HII regions, and computed their

The COMPTEL observations of the diffuse galactic 1.809 MeV emission attributed to the radioactive decay of 26Al have confirmed the diffuse nature of this interstellar emission line. One of the most significant features of the reconstructed intensity pattern is a flux enhancement in the direction of the Cygnus region. This region is fairly young and