5 papers
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…
Sharper Than Ever: Do Modern Observations Pin Down the Solar Radius to Converge on New Standards?
Jean-Pierre Rozelot, Alexander Kosovichev
Solar radius measurements and their variations -- if any -- are a difficult problem that has vexed researchers for decades. In this paper, we have attempted to clarify the various…
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…
Structure and Dynamics of the Sun's Interior Revealed by Helioseismic and Magnetic Imager
Alexander Kosovichev, Sarbani Basu, Yuto Bekki +43
High-resolution helioseismology observations with the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) provide a unique three-dimensional view of the…
Improving Our Knowledge of the Solar Near-Surface Shear Layer: The Special Case of the Leptocline
Jean-Pierre Rozelot, Alexander Kosovichev, Irina Kitiashvili
The discovery of the solar activity cycle was linked from the outset to the observation of the temporal variability of sunspots, which we know to be the result of complex processes…