The effect of scattering by dust internal to H II regions on their spectral characteristics has been studied on the basis of simple analytical models, for assumed universal optical parameters of the dust. A procedure to determine the external interstellar extinction and the internal gas to dust abundance ratio of H II regions has been developed and

A high resolution spectrum (Δλ = 0.2 Å) of the Population II star HD 76932 from the archive of the IUE satellite has been analysed in a search for measurable resonance absorption lines due to 9Be. Matching the observations by a synthesized model of the wavelength region around the doublet at 3130 Å gives a conservative upper limit for the abundance

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Observations carried out with a 8-13 micron grating-spectrometer of Mrk 231 and NGC 4151 are reported. The Mrk 231 data can be fitted to various thermal dust emission models or a single power law, with dust extinction. In all the model fits, except for that of graphite and silicon carbide grain emission, a component of silicate absorption of

The authors present the results of a survey made at 1.65 μm (H) and 2.2 μm (K) in 15 small areas on the galactic equator between l = 0° and l = 10°. 775 distinct objects were counted in a total area of 0.17 deg2 to limiting magnitudes H = 10.5 and K = 9.5 (equivalent to detecting M giants at 6 - 7 kpc). Source confusion was the limiting factor in

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