The Variable Star Observers Switzerland (VSOS) is a working group of the Swiss Astronomical Society. The members are engaged in the observation and the recording of the changing brightness of variable stars.

The Purpose of Amateur Variable Star Observing

Variable stars are important because they supply us with much information on specific stellar states. Dependent on the type we learn about their mass, radii, temperature, luminosity, inner and outer structure, composition, distance and evolution. Professionals are not able to observe all known variable stars. Therefore amateur astronomers can provide important scientific data. In the last years confidence in amateur work grew among professionals; data requests on specific object increased steadily. One of the most important concerns is the long-time behaviour of particular stars. This is the only way to arrange specific observations in other wavelenghts.

Data Archive

Each organization has its own data administration (unfortunately) and therefore its own rules for acquiring and transmitting data. To enable exchange of the results on an international level, indication of reference comparison stars is important. These stars are used for estimating the visual magnitude of the variable. Some organizations use finder and comparison charts which are readily distributed to the interested amateur.

Join our group! New observers are welcome at any time!

Please visit also our forum "SAG Fachgruppe Veränderliche".