28 citations · 28 across the 2 of their papers we have counts for
3 papers
astro-ph.SR2025
The long-term solar variability, as reconstructed from historical sources: Several case studies in the 17th -- 18th centuries
Hisashi Hayakawa
On a centennial timescale, solar activity was quantified based on records of instrumental sunspot observations. This article briefly discusses several aspects of the recent archiva…
astro-ph.SR2025★ 28 cited
Strong evidence of low levels of solar activity during the Maunder Minimum
V. M. S. Carrasco, H. Hayakawa, C. Kuroyanagi +2
The Maunder Minimum (MM) was a period of prolonged solar activity minimum between 1645 and 1715. Several works have identified a significant number of problematic spotless days in…
astro-ph.SR2024
The Solar and Geomagnetic Storms in May 2024: A Flash Data Report
Hisashi Hayakawa, Yusuke Ebihara, Alexander Mishev +16
In May 2024, the scientific community observed intense solar eruptions that resulted in a great geomagnetic storm and auroral extension, highlighting the need to document and quant…