STATISTICAL ANALYSIS FOR ASTRONOMICAL RECORDS OF THE HYEONJONG-DONGGUNG-ILGI (1649-1659)
UHN MEE BAHK1,2†, BYEONG-HEE MIHN1,2,3, KI-WON LEE4, SANG HYUK KIM1, JAE YEON HYUN1,3, YONG GI KIM2
1Korea Astronomy and Space Science Institute, Daejeon 34055, Korea
2Chungbuk National University, Cheongju 28644, Korea
3Korea University of Science and Technology, Daejeon 34113, Korea
4Daegu Catholic University, Gyeongsan 38430, Korea
We investigated the records of astronomical phenomena in the Hyeonjong-Donggung-Ilgi written by the educational office for a crown prince, Sigang-won, during the time of a crown prince of the king Hyeonjong (i.e., from 1649 to 1659). Of the total of 3,625 days, 3,044 astronomical accounts were compiled from astronomical records of 2,003 days. We classified these astronomical accounts into 16 items, grouped into five categories, and statistically analyzed each group. In our analysis, the accounts for atmospheric optical phenomena equates to 57.9% of the total, and for celestial phenomena visible during the daytime the percentage is 17.3%. The records related to the approach between two objects such as planets, moon, and stars account for 3.3%, and solar or lunar eclipses take up 0.6%. The ratio of accounts regarding meteor, comet, and fire light (火光) stand at 13.8%, 0.30%, and 6.8%, respectively. Sunny days account for 71.1% of all days per year during this period. We determined that the distribution of the fire light by month is similar to that of the solar halo. We also found that the astronomical records from the Annals of the Joseon Dynasty correspond to only 30% of those of the Hyeonjong-Donggung-Ilgi for the same period. In particular, the phenomena of celestial objects occurring outside the atmosphere are transmitted to the Annals of the Joseon Dynasty in a higher proportion than the phenomena inside the air. It is therefore necessary to use a historical diary like a Donggung-Ilgi to interpret the phenomena in the air such as atmospheric optical events, meteor, and fire light.