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Iwahashi Zenbei's Sunspot Drawings in 1793 in Japan
Hisashi Hayakawa, Kiyomi Iwahashi, Harufumi Tamazawa +2
Three Japanese sunspot drawings associated with Iwahashi Zenbei (1756-1811) are shown here from contemporary manuscripts and woodprint documents with the relevant texts. We reveale…
Long-Lasting Extreme Magnetic Storm Activities in 1770 Found in Historical Documents
Hisashi Hayakawa, Kiyomi Iwahashi, Yusuke Ebihara +8
Dim red aurora at low magnetic latitudes is a visual and recognized manifestation of geomagnetic storms. The great low-latitude auroral displays seen throughout East Asia on 16-18…
Records of Auroral Candidates and Sunspots in Rikkokushi, Chronicles of Ancient Japan from Early 7th Century to 887
Hisashi Hayakawa, Kiyomi Iwahashi, Harufumi Tamazawa +5
In this article, we present the results of the surveys on sunspots and auroral candidates in Rikkokushi, Japanese Official Histories from the early 7th century to 887 to review the…
Records of Sunspots and Aurora Candidates in the Chinese Official Histories of the Yuán and Míng Dynasties during 1261-1644
Hisashi Hayakawa, Harufumi Tamazawa, Yusuke Ebihara +4
Records of observations of sunspots and auroras in pre-telescopic historical documents provide useful information about past solar activity both in long-term trends and short-term…