Accuracy of Solar Eclipse Observations Made by Jesuit Astronomers in China

Stephenson, F. R.; Fatoohi, Louay

doi:10.1177/002182869502600302

Cited by 8 publications

(2 citation statements)

References 2 publications

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“…Stephenson and some researchers have identified hundreds of eclipse and occultation observations in early European, Middle Eastern and Chinese annals, manuscripts, canons and records. Also, some of them have fit a lot of records with simple polynomials to achieve best fits for describing the value of Δ T for centuries before ad 1600 (Morrison & Ward 1975; Stephenson & Morrison 1984; Stephenson & Houlden 1986; Stephenson & Fatoohi 1994; Stephenson & Fatoohi 1995; Stephenson 1997; Stephenson & Morrison 1995; Steele 1998; Morrison & Stephenson 2004). In spite of their relatively low precision, these data represent our only record of the value of Δ T during the past several millennia.…”

Section: Values Of δT and Analytical Relationsmentioning

confidence: 99%

A novel approach to delta-T from 1620 to 2010

Hakimi¹,

Setayeshi

2011

Monthly Notices of the Royal Astronomical Society

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Universal Time (ut) is a non‐uniform time‐scale based on the rotation of the Earth around its axis. Another time‐scale based on the duration of the SI second that was originally defined by the revolution of the Earth in its orbit around the Sun, is called Terrestrial Time (tt). As tt is a uniform time designed to provide continuity with the former Ephemeris Time (et), the difference between tt and ut is known as delta‐T (ΔT). The time series of ΔT values shows the variations in Earth rotation. There are several mathematical models to represent ΔT used in astronomical software and calculations. This paper discusses a new model for values of ΔT from 1620 to 2010 that uses artificial neural networks. The maximum absolute error in this model is about 0.5 SI second. The accuracy of the new model is compared with that of four prior models.

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Section: Values Of δT and Analytical Relationsmentioning

confidence: 99%

A novel approach to delta-T from 1620 to 2010

Hakimi¹,

Setayeshi

2011

Monthly Notices of the Royal Astronomical Society

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“…11 In addition, studies on the accuracies of solar and lunar eclipses in the Shixian calendar were performed by comparing them with the results of modern calculations. 12 Martzloff studied the mathematical methods adopted in Chinese calendars, including historical texts. 13 The decisive reason for implementing the Shixian calendar in the Qing dynasty was that it more precisely predicted the solar eclipse of 1644 than the previous Datong calendar.…”

Section: Introductionmentioning

confidence: 99%

Investigating calendrical methods of calculating sunrise and sunset times in the Shixian calendar

Choi,

Mihn,

Lee

2023

Journal for the History of Astronomy

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The Shixian calendar is the general name for Chinese calendars implemented in China’s Qing dynasty (1636–1912) and Korea’s Joseon dynasty (1392–1910). This calendar made under the influence of Western sciences was revised several times. Referring to the Yuzhi lixiang kaocheng, compiled by Mei Juecheng et al. in 1724, we analyze calendrical methods employed in the Shixian calendar for calculating sunrise and sunset times in terms of astronomy and mathematics. In astronomy, the Polaris was used to measure the latitude, and the Sun’s diurnal parallax was considered to increase accuracy. In mathematics, Western mathematics, such as trigonometric functions and properties of similar spherical triangles, were used to calculate sunrise and sunset times. In addition, ready reckoner tables were used to obtain the trigonometric values. The reproduced sunrise and sunset times are compared the results recorded in Shixian annual almanacs published in China and Korea to obtain the rules regarding dates on which these recording were made in the almanacs. We find that sunrise and sunset times were changed before and after around 1726 and in 1728 in the Shixian almanacs of China and Korea, respectively. Furthermore, we verify the values of the latitude and obliquity of the ecliptic used for calculating the sunrise and sunset times in the almanacs in each dynasty. This study will help understand the Shixian calendar and its annual almanacs in China and Korea.

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Solar Eclipses

Vaquero¹,

Vázquez²

2009

Astrophysics and Space Science Library

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Accuracy of Solar Eclipse Observations Made by Jesuit Astronomers in China

Cited by 8 publications

References 2 publications

A novel approach to delta-T from 1620 to 2010

A novel approach to delta-T from 1620 to 2010

Investigating calendrical methods of calculating sunrise and sunset times in the Shixian calendar

Solar Eclipses

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