Abstract
The Swiss Federal Observatory, which had been founded in 1863 by Rudolf Wolf, was dissolved in connection with the retirement of Max Waldmeier in 1979. The determination of the Zurich sunpot number, which had been a cornerstone activity of the observatory, was then discontinued by ETH Zurich. A smooth transition of the responsibility for the sunspot number from Zurich to Brussels was achieved in 1980, however, through which it was possible to avoid a discontinuity in this important time series. Here we describe the circumstances that led to the termination in Zurich, how Brussels was chosen for the succession, and how the transfer was accomplished.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Shapley, A.H.: 1979. Internal study for IAU Comm. 10, reported in a letter of 15 May 1979.
Waldmeier, M.: 1979, Tätigkeitsbericht der Eidgenössischen Sternwarte Zürich für das Jahr 1978/79, ETH, Zurich.
Author information
Authors and Affiliations
Corresponding author
Additional information
Sunspot Number Recalibration
Guest Editors: F. Clette, E.W. Cliver, L. Lefèvre, J.M. Vaquero, and L. Svalgaard
Rights and permissions
About this article
Cite this article
Stenflo, J.O. Transition of the Sunspot Number from Zurich to Brussels in 1980: A Personal Perspective. Sol Phys 291, 2487–2492 (2016). https://doi.org/10.1007/s11207-015-0837-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11207-015-0837-2