In nuclear medicine, there are two methods of imaging, planar and tomography. Single photon emission computerized tomography (SPECT) shows better image details and therefore is influenced more by image parameters such as resolution, uniformity, sensitivity, etc. Manufacturers provide customers with data which are obtained by complicated and sometimes secret methods. Marketing companies te...

We present mid-IR 21μm images of a sample of radio selected Ultracompact H ii (UCH ii) regions, obtained with the Midcourse Space Experiment (MSX). All, with one possible exception, are detected at mid-IR wavelengths, sampling the warm dust emission of the cocoons of the OB star central exciting sources. Many of the UCH ii regions have nearby (up to ≈ few pc distant) companion dust emission sou...

The observation of double stars by Hipparcos is modelled in order to check the statistics of double-star solutions in the Hipparcos Catalogue and to set quantitative limits on binary distributions. A Galaxy model is combined with models of binary distributions and of the observation process to derive the expected numbers of the different kinds of binary solutions in the Catalogue (component, ac...

We present a catalogue containing 839 candidate post common envelope systems. Common evolution is very important in stellar astrophysics, particularly the context of compact and short-period binaries, including cataclysmic variables, as progenitors e.g. supernovae type Ia or mergers black holes and/or neutron stars. At same time it barely understood process binary evolution. Due to limitations,...