We report new (1995) Very Large Array (VLA) observations and (1984-1999) Effelsberg 100 m monitoring observations of the 22 GHz H2O maser spectrum of the Seyfert 2 galaxy NGC 1068. The sensitive VLA observations provide a registration of the 22 GHz continuum emission and the location of the maser spots with an accuracy of ~5 mas. Within the

The term "Target of Opportunity" (ToO) is used in astronomy to identify unpredictable events whose study is of the highest scientific interest. For XMM-Newton a ToO is an astronomical event observable by its instruments, which cannot be predicted and scheduled on the time scale of one year, yet is scientifically significant enough to justify the

We have explored the effect of transition timescales in planetary nebulae (PNe) formation. We have performed hydrodynamical simulations of the evolution of the stellar winds predicted by theoretical stellar evolutionary models adopting two choices for the evolution during the transition time. The evolution of the star from the AGB to the PN stage

We have obtained high-resolution high signal-to-noise ratio spectra of the S I near-infrared doublet at 8694 Å in eight metal-poor stars with metallicities in the range -0.6

IRAS 10215-5916 was classified as a post-AGB star and also as a massive red supergiant. It was also found to be a spectroscopic binary. In our high resolution spectra we found molecular features from a cool star of Teff = 3750K. We also see the spectral signature of a relatively hotter star of Teff = 7250K. We found that both the components of the

HD 331319 is a F3 Ib star with a detached cold circumstellar dust shell with far-IR colours similar to planetary nebulae. From an analysis of high resolution spectra using LTE stellar atmospheric models, we have derived the atmospheric parameters and the chemical composition of HD 331319. By matching the theoretical and the observed spectrum we