The Solar Activity in the Dalton Minimum Revealed from Historical Documents in the Austrian Monasteries.


Hisashi Hayakawa (designated assistant professor), Shoma Uneme, and Shinsuke Imada (ex-lecturer) of the Division for Integrated Studies have conducted an international collaboration to analyse Stephan Prantner’s sunspot records preserved in Wilten Monastery (Austria) and construct the solar activity in the mid Dalton Minimum in terms of the sunspot group number and sunspot positions. Their result has shown a significant difference with the Maunder Minimum and provide an independent support to their existing analyses on the sunspot records in Kremsmünster Observatory and contemporary visual records on the solar coronal structure. Further studies will probably benefit the reconstructions of the long-term solar variability and its influence on the terrestrial environment. This result will be published in the Astrophysical Journal on 16 September 2021.

MS A07 03 07, f. 16 and f. 27b; ©︎ the Stiftsarchiv Wilten

Sunspot positions during the Dalton Minimum derived from Prantner’s sunspot observations.