The radial hydrogen (H2 + HI) distribution in spirals takes two forms: with a density peak at the nucleus or with a circular 'hole' around it. Spectral and photometric properties of selected spirals are examined, and cases of expansion in the circumnuclear gas, as well as ring structures in gas and stars are found. The correlation between absence

Not Available

The IRAS Point Source Catalog was cross-correlated with the Lynds Catalog of Dark Clouds to find bright IR sources with 100-micron fluxes higher than their corresponding fluxes at 60 microns. The objective was the detection of new candidates for bipolar molecular outflow sources and/or young embedded PMS stars associated with those clouds. Thirteen

Both linear and nonlinear analysis are used to gain a better understanding of the effects of multi-dimensional transfer of energy by radiation in spatially structured stellar atmospheres. Information on the radiative response of RE (radiative equilibrium) model atmospheres to temperature fluctuations is obtained. Whether or not such perturbed

The authors have measured the Li abundance in a sample of 37 field dwarfs of low metallicity. Stars with [Fe/H] -1.4 ("EMD" stars) form a much more homogenous population w.r.t. 7Li than do the stars with somewhat higher metallicities. The authors argue that the warmer EMD stars (6000K Teff 6300K) show little Li depletion, and that their

The authors present a spectroscopic analysis for the gravity determination of τ Ceti on the basis of a new and high quality set of data. The iron lines are studied by using the Oxford oscillator strengths. The results are compared with those obtained with "solar" oscillator strengths. Non-LTE effects seem to be important in this star. The Fe I at