44 citations · 80 across the 3 of their papers we have counts for
5 papers
Reanalyses of the Sunspot Observations of Fogelius and Siverus: Two "Long-Term" Observers during the Maunder Minimum
Hisashi Hayakawa, Tomoya Iju, Shoma Uneme +3
The solar activity during the Maunder Minimum (MM; 1645 -- 1715) has been considered significantly different from the one captured in modern observations, in terms of sunspot group…
SMART/SDDI Filament Disappearance Catalogue
Daikichi Seki, Kenichi Otsuji, Takako T. Ishii +8
This paper describes a new SMART/SDDI Filament Disappearance Catalogue, in which we listed almost all the filament disappearance events that the Solar Dynamics Doppler Imager (SDDI…
Thaddäus Derfflinger's sunspot observations during 1802-1824: A primary reference to understand the Dalton Minimum
Hisashi Hayakawa, Bruno P. Besser, Tomoya Iju +5
As we are heading towards the next solar cycle, presumably with a relatively small amplitude, it is of significant interest to reconstruct and describe the past grand minima on the…
Temporal and Spatial Evolutions of a Large Sunspot Group and Great Auroral Storms around the Carrington Event in 1859
Hisashi Hayakawa, Yusuke Ebihara, David M. Willis +10
The Carrington event is considered to be one of the most extreme space weather events in observational history within a series of magnetic storms caused by extreme interplanetary c…
Revisiting Kunitomo's Sunspot Drawings during 1835-1836 in Japan
Masashi Fujiyama, Hisashi Hayakawa, Tomoya Iju +7
We revisit the sunspot drawings made by the Japanese astronomer Kunitomo Toubei during 1835-1836 and recount the sunspot group number for each image. There are two series of drawin…