The Stellar Occultation Timing Association Switzerland (SOTAS) is a working group of the Swiss Astronomical Society. The members are engaged in the observation and the recording of occultations of stars, caused by astronomical bodies such as asteroids, moons and planets.

The objective of our work includes the precise determination of the moment of the disappearing and re-appearing of the light of an occulted star, observed from a well known location. The knowledge of exact time and observing site of an occultation event allows

     - to determine size and shape of the occulting body,

     - to detect double bodies and accompanying satellites,

     - to adjust the orbital elements of the occulting body.


Each observation will be reported to the European Section of the International Occultation Timing Association (IOTA/ES). Doing so, the group provides valuable data for astronomical science.

In addition, our members provide information, recommendations and support on observing equipment and techniques.

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

Please visit also our forum "SAG Fachgruppe Sternbedeckungen".