61 citations · 249 across the 8 of their papers we have counts for
8 papers
A Great Space Weather Event in February 1730
Hisashi Hayakawa, Yusuke Ebihara, José M. Vaquero +9
Aims. Historical records provide evidence of extreme magnetic storms with equatorward auroral extensions before the epoch of systematic magnetic observations. One significant magne…
Sunspot Drawings by Japanese Official Astronomers in 1749-1750
Hisashi Hayakawa, Kiyomi Iwahashi, Masashi Fujiyama +7
Sunspot observations with telescopes in 18th century were carried out in Japan as well. One of these sunspot observations is recorded in an account called Sansaizusetsu narabini Ka…
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Long-Lasting Extreme Magnetic Storm Activities in 1770 Found in Historical Documents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…
Historical Auroras in the 990s: Evidence for Great Magnetic Storms
Hisashi Hayakawa, Harufumi Tamazawa, Yurina Uchiyama +5
Recently, a significant carbon-14 enhancement in the year 994 in tree rings has been found, suggesting an extremely large cosmic ray flux event during a short period. The origin of…
The earliest drawings of datable auroras and a two-tail comet from the Syriac Chronicle of Zūqnīn
Hisashi Hayakawa, Yasuyuki Mitsuma, Yasunori Fujiwara +7
People have probably been watching the sky since the beginning of human history. Observers in pre-telescopic ages recorded anomalous events and these astronomical records in the hi…
East Asian Observations of Low Latitude Aurora during the Carrington Magnetic Storm
Hisashi Hayakawa, Kiyomi Iwahashi, Harufumi Tamazawa +6
The magnetic storm around 1859 September 2, caused by so-called Carrington flare, was the most intense in the history of modern scientific observations, and hence is considered to…