We present the results of optical and near-IR spectra and mid-infrared images of the star-forming region Gy 2-18, which is associated with IRAS 05439+3035.

We derived consistent photospheric and wind parameters of O-type stars, by analyzing high-resolution spectra in the range 905 to 3250 Å with line-blanketed, hydrodynamic, non-LTE spherical models. We find significantly lower T[eff] and luminosities than previously assigned to these spectral types.

We have imaged the planetary nebula (PN) NGC 246 in the wavelengths [Ne V] 342.6 nm, O III at 344.4 nm, and a nearby line-free region at 338.6 nm, as well as H alpha , [O III] 500.7 nm, and [S II] 673.0, 671.5 nm.

The standard Non-LTE problem consists in calculating the atomic level populations that are consistent with the intensity of the radiation field generated within any given stellar atmospheric model. In contrast, the Non-LTE problem of the second kind is, indeed, like an ``algebraic Annapurna'': it requires to calculate the diagonal and non-diagonal

We explore the relationship between the hard X-ray and submillimetre populations using deep Chandra observations of a large, contiguous SCUBA survey. In agreement with other recent findings, we confirm that the direct overlap is small. Of the 17 submillimetre sources detected in this field at 850 μm, only one is coincident with a Chandra source

In this article we present a detailed spectroscopic analysis of more than 50 extra-solar planet host stars. Stellar atmospheric parameters and metallicities are derived using high resolution and high S/N spectra. The spectroscopy results, added to the previous studies, imply that we have access to a large and uniform sample of metallicities for