Since many years, Swiss amateur astronomers are engaged in the observation and the recording of occultations of stars, caused by astronomical bodies such as asteroids, moons and planets. 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. This site documents the activities and shows the results of the observations.

Swiss Occultation Numbers

The Swiss Occultation Numbers (SON) are a statistical summary of the monthly observations and are frequently published in the astronomical magazine "ORION".

Swiss Occultation Numbers


The following links contain the reports of observed occultations, made by SOTAS members and sorted by the year of observation.
In prominent cases, they are completed with the chords, resulted in combination with observers of the IOTA/ES community.
The chords are calculated and illustrated by Eric Frappa (euraster.net), with many thanks for the permission to publish.

2020 2019 2018 2017 2016
2015 2014 2013 2012 2011
2010 2009 2008 2007 2006
2005 2004 2003 2002 2001
2000 1999 1998 1997 1996
1995 1994 1993 1992 1991
1990 1989 1988 1987 1986
1985 1984 1983 1982 1981

Summary Reports

2017 Summary Report Minor Planet Circular (vacant).
2016 Summary Report Minor Planet Circular 104988.
2015 Summary Report Minor Planet Circular   94399.
2014 Summary Report Minor Planet Circular   89395.


Star occultations
in Switzerland
Die positiven Sternbedeckungen in der Schweiz von 1997 bis 2017 (und auch vorher).
by Stefano Sposetti.
Ancient article about a visual observation
(Orion No. 243)
Eine Sternbedeckung durch einen Planetoiden.
by Christof Sauter.