The Purple Mountain Observatory (), also known as Zijinshan Astronomical Observatory, is an astronomical

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

located on the

Purple Mountain Purple Mountain may refer to: China * Purple Mountain (Nanjing), a mountain in Nanjing, Jiangsu Ireland * Purple Mountain (Kerry), a mountain in County Kerry United States * Purple Mountain (Alaska), a mountain in Alaska * Purple Mountain ...

in the east of

Nanjing Nanjing or Nanking is the capital of Jiangsu, a province in East China. The city, which is located in the southwestern corner of the province, has 11 districts, an administrative area of , and a population of 9,423,400. Situated in the Yang ...

. The observatory is responsible for calculating the official

Chinese calendar The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for officia ...

mainland China "Mainland China", also referred to as "the Chinese mainland", is a Geopolitics, geopolitical term defined as the territory under direct administration of the People's Republic of China (PRC) in the aftermath of the Chinese Civil War. In addit ...

Description

The Purple Mountain Observatory was established in 1934 funded by the

Nationalist Government The Nationalist government, officially the National Government of the Republic of China, refers to the government of the Republic of China (1912–1949), Republic of China from 1 July 1925 to 20 May 1948, led by the nationalist Kuomintang (KMT ...

of the

Republic of China Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

and administered by

Academia Sinica Academia Sinica (AS, ; zh, t=中央研究院) is the national academy of the Taiwan, Republic of China. It is headquartered in Nangang District, Taipei, Nangang, Taipei. Founded in Nanjing, the academy supports research activities in mathemat ...

. The longtime director of the observatory from 1950 to 1984 was Chinese astronomer

Zhang Yuzhe Zhang Yuzhe (; 16 February 1902 – 21 July 1986), also known as Yu-Che Chang, was a Chinese astronomer and director of the Purple Mountain Observatory who is widely regarded as the father of modern Chinese astronomy. He studied the light curv ...

(, 1902–1986, also known as Y. C. Chang). By the late 1980s, increasing

light pollution Light pollution is the presence of any unwanted, inappropriate, or excessive artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting sources, during the ...

in Nanjing meant Purple Mountain was no longer viable as a working observatory. It has since shifted its focus to public education, with much of the actual scientific work being carried out in its five branch observatories located at

Qinghai Qinghai is an inland Provinces of China, province in Northwestern China. It is the largest provinces of China, province of China (excluding autonomous regions) by area and has the third smallest population. Its capital and largest city is Xin ...

(in

Delingha Delingha ( zh, s=德令哈; ), or Delhi (), is the seat of the Haixi Mongol and Tibetan Autonomous Prefecture in northern Qinghai province, China. It is located approximately southeast of the Da Qaidam Administrative Region. It is a mainly indu ...

), Ganyu,

Xuyi Xuyi is a county under the administration of Huai'an Prefecture in central Jiangsu Province in eastern China. The southernmost of Huai'an's county-level divisions, it borders the prefecture-level cities of Suqian, Jiangsu, to the north and Chuzh ...

, Honghe (in

Jiamusi Jiamusi (Manchu: ; formerly Kiamusze) is a prefecture-level city in eastern Heilongjiang province, People's Republic of China. Located along the middle and lower reaches of the Songhua River, it faces Russia's Khabarovsk Krai across the Ussuri ...

), and

Qingdao Qingdao, Mandarin: , (Qingdao Mandarin: t͡ɕʰiŋ˧˩ tɒ˥) is a prefecture-level city in the eastern Shandong Province of China. Located on China's Yellow Sea coast, Qingdao was long an important fortress. In 1897, the city was ceded to G ...

. The

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

credits the observatory, simply referred to as Nanking, with the discovery of 149

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

s between 1955 and 1983, while the observatory's PMO NEO Survey Program is credited with more than 600 discoveries between 2006 and 2013.

Discoveries

The observatory discovered the periodic

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

60P/Tsuchinshan 60P/Tsuchinshan, also known as Tsuchinshan 2, is a periodic comet in the Solar System with an orbital period of 6.79 years. Tsuchinshan is the Wade-Giles transliteration corresponding to the pinyin ''Zǐjīn Shān'' '' 紫金山'', which is Man ...

and

62P/Tsuchinshan 62P/Tsuchinshan, also known as Tsuchinshan 1, is a periodic comet first discovered January 1, 1965 at the Purple Mountain Observatory in Nanjing. It last came to perihelion on 25 December 2023 at around apparent magnitude 8, and was then from ...

, as well as the non-periodic (Tsuchinshan), also known as Comet 1977 X, , and C/2023 A3 (Tsuchinshan-ATLAS). They are named after the

postal romanization Postal romanization was a system of transliterating place names in China developed by postal authorities in the late 19th and early 20th centuries. For many cities, the corresponding postal romanization was the most common English-language fo ...

of the name (

Wade–Giles Wade–Giles ( ) is a romanization system for Mandarin Chinese. It developed from the system produced by Thomas Francis Wade during the mid-19th century, and was given completed form with Herbert Giles's '' A Chinese–English Dictionary'' ...

: ''Tzu-chin-shan'';

pinyin Hanyu Pinyin, or simply pinyin, officially the Chinese Phonetic Alphabet, is the most common romanization system for Standard Chinese. ''Hanyu'' () literally means 'Han Chinese, Han language'—that is, the Chinese language—while ''pinyin' ...

: ''Zǐjīnshān''). Many

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

s were also discovered, including the

Trojan asteroid In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points and . Trojans can shar ...

s 2223 Sarpedon, 2260 Neoptolemus, 2363 Cebriones,

2456 Palamedes 2456 Palamedes is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 30 January 1966, by astronomers at the Purple Mountain Observatory in Nanking, China. The assumed C-type asteroid has a rotation peri ...

, and the eponymous 3494 Purple Mountain.

Near-Earth object survey

The ''Chinese Near-Earth Object Survey'' (CNEOS), based at the Xuyi Station in

Jiangsu Jiangsu is a coastal Provinces of the People's Republic of China, province in East China. It is one of the leading provinces in finance, education, technology, and tourism, with its capital in Nanjing. Jiangsu is the List of Chinese administra ...

, started observations in 2006. It uses a 1:04=1:20=1:80 m

Schmidt telescope Schmidt may refer to: * Schmidt (surname), including list of people and fictional characters with the surname * Schmidt (singer) (born 1990), German pop and jazz singer * Schmidt (lunar crater), a small lunar impact crater * Schmidt (Martian c ...

equipped with a 4K × 4K CCD detector with the drift-scanning function. As of August 2012, the program has observed 149,971 asteroids, found 1,279 new provisional designation asteroids, and cataloged 251 numbered asteroids including five

Jupiter trojan The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each Trojan (celestial body), trojan Libration point orbit, librat ...

s, two Hildian, and one

Phocaea Phocaea or Phokaia (Ancient Greek language, Ancient Greek: Φώκαια, ''Phókaia''; modern-day Foça in Turkey) was an ancient Ionian Ancient Greece, Greek city on the western coast of Anatolia. Colonies in antiquity, Greek colonists from Phoc ...

asteroid. The program has also observed the position of 824

near-Earth object A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...

s (NEOs) and discovered four new ones: the

Apollo asteroid The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Ear ...

, and the three Amor asteroid , , and .

List of discovered minor planets (1955–1983)

A total of 149

s were discovered by the Purple Mountain Observatory between 1955 and 1983.

List of discoveries by the PMO NEO Survey Program

Several hundred minor planets were discovered by the observatory's PMO NEO Survey Program from 2006 to 2013.

Image gallery

File:PurpleMountainObservatory01.JPG, Gate of the Purple Mountain Observatory File:Purple Mountain Observatory - Xuyu Station Door.jpg, Entrance at the Xuyi Station File:Purple Mountain Observatory - Xuyu Station.jpg, Telescope at Xuyi Station

References

External links

Purple Mountain Observatory website
{{Authority control Astronomical observatories in China Buildings and structures in Nanjing * * Minor-planet discovering observatories Major National Historical and Cultural Sites in Jiangsu Research institutes of the Chinese Academy of Sciences