3 papers
physics.hist-ph2020
Provenance of the Cross Sign of 806 in the Anglo-Saxon Chronicle: A possible Lunar Halo over Continental Europe?
Yuta Uchikawa, Les Cowley, Hisashi Hayakawa +2
While graphical records of astronomical/meteorological events before telescopic observations are of particular interest, they have frequently undergone multiple copying and may hav…
astro-ph.SR2019
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…
astro-ph.SR2019
A Transit of Venus Possibly Misinterpreted as an Unaided-Eye Sunspot Observation in China on 9 December 1874
Hisashi Hayakawa, Mitsuru Sôma, Kiyotaka Tanikawa +6
Large sunspots can be observed with the unaided eye under suitable atmospheric seeing conditions. Such observations are of particular value because the frequency of their appearanc…