2024-03-28T23:39:35Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:02002051
2023-01-16T05:07:26Z
2026:2027:2028
Stephan Prantner’s Sunspot Observations during the Dalton Minimum
Hayakawa, Hisashi
Uneme, Shoma
Besser, Bruno P.
Iju, Tomoya
Imada, Shinsuke
open access
© 2021. The American Astronomical Society
Sunspots
Sunspot cycle
Sunspot groups
Solar-terrestrial interactions
Maunder minimum
In addition to regular Schwabe cycles (≈11 yr), solar variability also shows longer periods of enhanced or reduced activity. Of these, reconstructions of the Dalton Minimum provide controversial sunspot group numbers and limited sunspot positions, partially due to limited source record accessibility. In this context, we analyzed Stephan Prantner's sunspot observations spanning from 1804 to 1844, the values of which had only been known through estimates despite their notable chronological coverage during the Dalton Minimum. We identified his original manuscript in Stiftsarchiv Wilten, near Innsbruck (Austria). We reviewed his biography (1782–1873) and located his observational sites at Wilten and Waidring, which housed the principal telescopes for his early and late observations: a 3.5 inch astronomical telescope and a Reichenbach 4 foot achromatic erecting telescope, respectively. We identified 215 days of datable sunspot observations, which is almost twice as much data as his estimated data in the existing databases (=115 days). In Prantner's records, we counted up to seven to nine sunspot groups per day and measured sunspot positions, which show their distributions in both solar hemispheres. These results strikingly emphasize the difference between the Dalton Minimum and the Maunder Minimum as well as the similarity between the Dalton Minimum and the weak solar cycles in the modern observations.
IOP publishing
2022-02-08
2021-09-20
eng
journal article
VoR
http://hdl.handle.net/2237/0002002051
https://nagoya.repo.nii.ac.jp/records/2002051
https://doi.org/10.3847/1538-4357/abee1b
0004-637X
The Astrophysical Journal
919
1
1
https://nagoya.repo.nii.ac.jp/record/2002051/files/Hayakawa_2021_ApJ_919_1.pdf
application/pdf
1.2 MB
2022-02-08