Solar eclipses observed worldwide in the first half of the 15th century and ΔT determined from multiply observed eclipses

Abstract

Abstract The main purpose of the present paper is to list all the solar eclipses which took place in the first half of the 15th century, to list all the available records of observation of these eclipses, and, by using the multiply observed or contemporaneously observed solar eclipses, to determine ΔT for a few periods of the first half of the 15th century. We make the table using solar eclipse records from East Asia (China, Korea, and Japan), India, West Asia, and Europe, though the table is not perfect because the compilation of records is not complete in some of the relevant areas. We evaluate the reliability of the Chinese records of solar eclipses. The Chinese official history book, the Mingshi, records visible eclipses, while it does not record invisible eclipses. A simple analysis shows that the reliability of the book is $97\%$. The marginally observable eclipses in China are useful for us to determine ΔT. We briefly consider the Māori eclipse observed in 1409. We extract the multiply observed eclipses and check whether these are useful for determining the value of ΔT. Finally, with newly added records of solar eclipses, we re-determine the value range of ΔT during the years 1431–1433 (see Tanikawa et al. 2019, in Proc. 5th Symposium on Historical Astronomical Records and Modern Science), and add a new ΔT in the year 1445.