activity
20132021
most citedTemporal and Spatial Evolutions of a Large Sunspot Group and Great Auroral Storms around the Carrington Event in 1859

98 citations · 275 across the 11 of their papers we have counts for

collaborators

11 papers

astro-ph.SR2021★ 16 cited

Stephan Prantner's Sunspot Observations during the Dalton Minimum

Hisashi Hayakawa, Shoma Uneme, Bruno P. Besser +2

In addition to regular Schwabe cycles (~ 11 years), solar activity also shows longer periods of enhanced or reduced activity. Of these, reconstructions of the Dalton Minimum provid…

astro-ph.SR2021★ 16 cited

Daniel Mögling's sunspot observations in 1626 - 1629: A manuscript reference for the solar activity before the Maunder Minimum

Hisashi Hayakawa, Tomoya Iju, Koji Murata +1

The sunspot groups have been observed since 1610 and their numbers have been used for evaluating the amplitude of solar activity. Daniel Mögling recorded his sunspot observations f…

astro-ph.SR2020★ 22 cited

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…

astro-ph.SR2020

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…

astro-ph.SR2020★ 44 cited

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…

astro-ph.SR2019★ 15 cited

Sunspot Observations by Hisako Koyama: 1945-1996

Hisashi Hayakawa, Frédéric Clette, Toshihiro Horaguchi +4

The sunspot record is the only observational tracer of solar activity that provides a fundamental, multi-century reference. Its homogeneity has been largely maintained with a succe…