| Popis: |
Discussed are meritorious projects for small and moderate telescopes in the field of interacting binaries with non-degenerate component stars. These interacting binaries are undergoing a mass transfer process, as a consequence of which the mass-accreting star may be partly or completely hidden in an accretion disk, and the system may be shrouded in dense clouds of circumstellar matter. This makes the observation, interpretation and modeling difficult; but it is important to study these “bizarre” binaries since they tell us a lot about stellar evolution in binary systems. Needed are various observations: Timing of eclipses; observation and re-observation of light curves in several colors (in uvby rather than in UBV; and in the red and infrared); radial velocity studies; spectrophotometry of crucial regions of the spectrum. As examples for these needs, the following systems are discussed in some detail, and their problems revealed: RX Cassiopeiae, W Serpentis, and W Crucis as examples of the strongly interacting systems (W Serpentids); U Sagittarii as a helium-rich binary in a rare evolutionary stage, which will be better understood if we decide whether the star eclipses or not; and KX Andromedae as a representative of non-eclipsing interacting binaries and of Be and shell stars, which may or may not be binaries. |
