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. By presenting detailed archive metadata and high-quality digital reproductions of original drawings online in the e-manuscripta.ch portal, access to this unique observation series will be optimized and simplified for solar research.

Description of the project

Observation of sunspots began in 1884 using projection image drawings at the Zurich observatory, and was passed on as an ongoing series from 1887 to 1995. In an initial phase, around 23,000 drawings of the observation staff under the respective direction of Rudolf Wolf, Alfred Wolfer and William Brunner will be indexed and digitized by the end of 2016.

From 1947, Helmut Müller assumed responsibility for recording sunspots. A subsequent project will see the indexing and digitization of the later 27,000 or so drawings from the series made at the main Zurich observatory – with additions particularly from Locarno-Monti.

Synergies and context

International solar research

June to December 2016:Project duration

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