Sunspot Observations and Counting at Specola Solare Ticinese in Locarno since 1957

Abstract

Specola Solare Ticinese is an observatory dedicated to Sunspot Number counting, which was constructed in 1957 in Locarno, Southern Switzerland, as an external observing station of the Zurich Federal Observatory. When in 1981 the responsibility of the determination of the International Sunspot Number was assumed by the Royal Observatory of Belgium, Specola Solare Ticinese was given the role of pilot station, with the aim of preserving the continuity in the counting method. We report the observing procedure and counting rules applied in Locarno.

arXiv comment7 pages, 5 figures

References in corpus (2)

• Revisiting the Sunspot Number
• Transition of the Sunspot Number from Zurich to Brussels in 1980: A Personal Perspective

Cited by in corpus (7)

• Re-calibration of the Sunspot Number: Status Report
• Sunspot Observations by Hisako Koyama: 1945-1996
• Reconstruction of the Sunspot Number Source Database and the 1947 Zurich Discontinuity
• A Sunspot Catalog for the Period 1952-1986 from Observations Made at the Madrid Astronomical Observatory
• Eric Strach: four decades of detailed synoptic solar observations (1969-2008)
• Testing the accuracy of Coimbra Astronomical Observatory solar filament historical series (1929-1941)
• Sunspot data collection of Specola Solare Ticinese in Locarno