Digitization of sunspot drawings

Aim of the project

Internationally and in scientific circles, there is strong interest in the sunspot drawings stored in the ETH Zurich University Archives. The observation of the sunspots using projection drawings at the Zurich Observatory began in 1884. The drawings from the period 1887 to 1995 are available as a continuous series. With the online presentation of detailed archival metadata and high-quality digital reproductions of the original drawings in the portal e-manuscripta.ch the access for solar research to this unique series of observation will be optimised and simplified.

Description of the project

In the first phase, around 20,000 drawings and 16,800 pages of tabular data series of the observation staffs of the first 60 years were archived and subsequently digitized.

In a second phase, the sunspot drawings, which have been placed in the analogue "data archive" since the 1940s, are catalogued and digitized in detail. The cataloguing of the main series, complemented by new series of observations, above all, by the full range of drawings that the Locarno-Monti observatory created after the Second World War, was started in 2017.

Synergies and context

International solar research, climate monitoring

Subnavigation and related Informations

Related Informations Digitization of sunspot drawings


Christian J. Huber 
Head of ETH Zurich University Archives
+41 44 632 07 04

Christian Huber