• 천문학논총
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• 제22권4호
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• pp.151-168
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• 2007

We have analyzed the comet records in the Korean history books: Samguksagi, Goryeosa, and Joseonwangjosillok. For a comparison, the Chinese and Japanese comet records collected by Kronk (1999) have also been analyzed. Power spectrum of the time series of the comet records is used to find periodic comets. Statistically significant periodicities in the power spectrum are detected at the periods of 38-40 years, about 76 years, and 300-400 years for all Korean, Chinese, and Japanese comet records. We have also calculated the past orbits of some comets that have been recently observed, to check whether or not they were recorded in the history books. We use a multistep method to numerically integrate the comet's orbital motion backward in time to 51 B.C. The gravitational force due to the Sun and the nine planets, non-gravitational force, and the relativistic effects have been considered. Comparison of comet's perihelion passage time and the position on the sky with the historical records shows that the comet Halley were recorded at every passage in both Goryeo and Joseon periods. The orbital motion of the comet Pons-Brooks has also been compared with the Korean records. For the comet Tempel-Tuttle, Swift-Tuttle, and Ikeya-Zhang, we have compared our calculation of the orbital motions with those of the previous studies.

• 천문학회지
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• 제1권1호
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• pp.19-27
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• 1968

A simple method for solar-lunar calendar conversion is obtained by means of Meton period for the convinience of the date conversion in the study of the old records of astronomical observations in Korea.

• 천문학회보
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• 제24권1호
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• pp.45-45
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• 1999

• 천문학회지
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• 제29권spc1호
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• pp.439-440
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• 1996

The Chinese ancient accounts of timing observations of 48 lunar eclipses and the secular variation of the Earth's spin speed are discussed. A series of ${\Delta}$T expressing the secular deceleration of the Earth's rotation was obtained. The average increase rate of length of the day is about 1.5 milliseconds per century.

• 천문학논총
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• 제30권2호
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• pp.713-714
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• 2015

Indian astronomical texts have records of lunar astronomy since the Puranic age. In the Vednga Jyotia (1350 B CE), the algorithm for computing eclipses is not found. This phenomenon was interpreted in the Siddhntic texts as the occurrence of Vyatipati Yoga. This paper attempts to explain the computing and observational method found in astronomical texts of Siddhntic period.

• 천문학회지
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• 제6권1호
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• pp.1-8
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• 1973

Presumable explosion time of Cas A has been listed from Dec. 6, 1592 to Mar. 5, 1593 in ancinet Korean observational records. It may have been overlooked, due to other supernova(Cassiopeia Nova) which appeared at that time near its original position of Cas A.

• 한국지구과학회지
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• 제29권5호
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• pp.408-418
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• 2008

In this study, solar eclipse records were investigated during the Three Kingdoms era of ancient Korea using astronomical calculations and numerical simulations. Under the condition that the solar eclipses were actually observed at the well known capitals of the Three Kingdoms, I investigated the probabilities that the optimal observation areas of the Early Silla, Goguryeo, and Baekje records would appear around Chinese continent. I found higher probabilities than those suggested by Park and La (1994), although the numerical values are still low, especially in the case of the Early Silla records. On the other hand, the probability that the optimal observation area of the Later Silla records will be present around South Korea is only 13.6%, although the area shows a good match with the known capital. I also analyzed the number distribution of the eclipse records for the Three Kingdoms (except for the latter Silla's) according to the observers' locations: at the optimal observation areas and at the known capitals. And then I compared with the number distribution of all eclipses observable from those locations. From the $\chi^2$-test, I found that the Goguryeo and Baekje records had better representation of their population distributions at the latter regions ($\chi^2$=27.93 and 205.5) than at the former ones ($\chi^2$=34.19 and 211.5). Therefore, it is difficult to conclude that the observers' locations during the Three Kingdoms period were either near China, as suggested by Park and La, or in the Korean peninsula, solely based on these results. It is thus recommended that more studies are required to confirm the real observers' locations during the Three Kingdoms era.

• 천문학회보
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• 제39권1호
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• pp.85.2-85.2
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• 2014

The origin of the Korean Screen Planisphere with both Traditional and New Star-Charts, made by Korean Astronomers in the Royal Astronomical Bureau of the Joseon Dynasty by adopting the knowledge of the European astronomy, is investigated by analyzing its inscriptions and star charts. The considerations on both the changes in notations or representations of names of asterisms and the naming taboos used in the Old-style planisphere imply that the star-chart is originated from either the Sukjong-Stele-Replica of Cheonsang-Yeolcha-Punyajido(天象列次分野之圖). The New style planisphere is just the reproduction of Huangdao-congxingtu (黃道總星圖), with the exception of the non-Chinese-traditional stars. The Huangdao-congxingtu was made in 1723 CE by Ignatius K$\ddot{o}$gler who was a Jesuit missionary and worked for the Bureau of Astronomy (欽天監) in the Qing Dyansty. I find that the star chart was imported in 1742 CE from the Qing by An Gukrin (安國麟) who was an astronomer in the Royal Astronomical Bureau of Joseon. The chart became model for the screen star-chart made in 1743 CE and now housed in Bopju temple. I found that the inscriptions are extracted from the sentences in both Xinzhi Lingtai Yixiangzhi (新製靈臺儀象志) and Qinding Yixiangkaocheng (欽定儀象考成). Korean historical records in either Daily Records of the Royal Secretariat of the Joseon Dynasty (承政院日記) or Annals of the Joseonn Dynasty (朝鮮王朝實錄) show that Xinzhi Lingtai-Yixiangzhi was imported from the Qing Dynasty in 1708 CE, and the Qinding Yixiangkaocheng was imported in 1766 CE. Thus, the Korean Screen Planisphere with both Old and New Star-charts was certainly made after 1766 CE.

• 천문학논총
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• 제31권1호
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• pp.1-9
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• 2016

We investigate the records related to the reign style and the calendar day from the epigraphs of the Goryeo dynasty (918 - 1392) in Korea in order to verify and supplement the sexagenary cycle data of the first day in the lunar month of the dynasty. The database of the National Research Institute of Culture Heritage contains a rubbed-copy image, transcription statement, and translation statement for Korean epigraphs as well as 775 epigraphs corresponding to the Goryeo dynasty. The epigraph records are valuable in that, during this time, they were written differently from other historical literature such as the Goryeosa (History of the Goryeo Dynasty), which was compiled in the next dynasty. We find that the Goryeo dynasty, in general, had adopted the reign styles of Chinese dynasties at that time. We also find 159 calendar day records all showing good agreement with the work of Ahn et al. except for dozens of records. Through this study, we can verify the reign styles and the calendar days of the Goryeo dynasty.

• 천문학논총
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• 제33권3호
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• pp.31-44
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• 2018

Song, I-Yeong (1619 ~ ?) was an active astronomer in the Joseon dynasty at the era of adopting the Shixian-li, Chinese calendar in Qing dynasty. His astronomical contribution was recorded in Annals of the Joseon Dynasty, Diary of the Royal Secretariat, Comparative Review of Records and Documents-Its Revision and Enlargement, and Treatise on the Bureau of Astronomy. In addition the details on his life and works were found at the genealogies of the Song Family from Yeonan and the Kim Family from Seonsan. His major astronomical activities can be summarized in three items. First, as a specialist astronomer, he has attempted to make a systematic observation of two comets. Second, he designed and fabricated the Jamyeong-jong, the weight-powered armillary clock, which became a typical model of the astronomical clock in the Joseon dynasty. Last, he served as a royal astronomical professor, greatly contributing on implementing the Shixian-li. Song has concentrated on performing astronomical duties for his royal official service time. Song is regarded as an important astronomer who made it possible to enforce the Shixian-li until the late Joseon dynasty.