Osservatorio astronomico della Specola Solare

Osservatorio astronomico della Specola Solare

The Specola Solare Ticinese started the activity in 1957 as one of the federal observatories of ETH Zurich. The Specola was specialized from the beginning in the observation of the solar activity and in particular in the determination of the international index of solar activity called Wolf number.

Since 1981 ETH did not include the solar activity determination in its scientific program anymore and it renounced to continue the operation of the observatory. The determination of the Wolf number was took over by the “Sunspot Index Data Center” (SIDC) in Bruxelles. The continuation of the operation of the Specola Solare Ticinese was guaranteed by a local association called Associazione Specola Solare Ticinese (ASST), which was founded for that purpose.

At present the main scientific goal of the Specola is still the determination of the Wolf number. The data collected at the Specola are sent regularly to the SIDC, where the Specola is considered the world reference station.









  • A Zeiss refractor (150 mm opening) in an hemispheric dome (used for the sunspot drawings)
  • Coelostat (200 mm) and a refractor (140 mm) followed by an optical bench with spectrographs and monochromatic filters.

For night observations the following instrument is also available:

  • Maksutov-Cassegrain refractor D=300 mm F=4800 mm with a teleobjective Prakticar-Pentacon (500 mm F/5.6) and a CCD camera.







Anschrift Specola Solare Ticinese
via ai Monti 146
6600 Locarno
Telefon +41 91 220 60 01
E-Mail cagnotti@specola.ch
Website http://www.specola.ch/e/
Koordinaten 46.172336 / 8.787919
Sektion SAT