3 papers
astro-ph.SR2026
Analyses on Christoph Clavius' Reports of Total Solar Eclipses in 1560 and 1567: Key References for the Centennial Variations of the Earth's Rotation Speed and the Solar Radius
Hisashi Hayakawa, Mitsuru Sôma, Jean-Pierre Rozelot +4
Variations in solar radius (hereafter R_Sun) is a key reference for solar magnetic activity in time. The sunlight amount may have varied with R_Sun and had an effect on the Earth's…
astro-ph.SR2026
Analyses on Wassenius' Report for Total Solar Eclipse in 1733: Quantifications of the Solar Radius and the Earliest Reported Prominences
Hisashi Hayakawa, Mitsuru Sôma, Noortje Peek +3
Total solar eclipses (TSEs) offer a unique opportunity to observe the solar atmosphere, detect limb phenomena, and accurately measure the solar radius. Following the TSE in 1733, W…
astro-ph.EP2026
Variable Earth's Rotation Speed in the 14th to 16th Centuries: New ÎT Constraints from Chinese Eclipse Records
Hisashi Hayakawa, Mitsuru Sôma, Naiqi Li
Total solar eclipses are not only astronomical spectacles but also great astrophysical laboratories. Their historical records are particularly helpful for assessing the past variab…