Zhang Yuzhe

In thisChinese name,thefamily nameisZhang (Chang).

Zhang Yuzhe(Chinese:Trương ngọc triết;16 February 1902 – 21 July 1986), also known asYu-Che Chang,was a Chineseastronomerand director of thePurple Mountain Observatorywho is widely regarded as the father of modern Chinese astronomy.He studied thelight curvesof asteroids, and thus theirrotation periods.He also researched thevariable starCZ Cassiopeiae and the evolution of the orbit ofComet Halley.Zhang discovered threecometsand is credited under the nameY. C. Changby theMinor Planet Centerfor the discovery of oneminor planet,the outer main-belt asteroid3789 Zhongguo.

Zhang Yuzhe
Trương ngọc triết
Born	(1902-02-16)16 February 1902 Fuzhou,Minhou
Died	21 July 1986(1986-07-21)(aged 84)
Education	Tsinghua University University of Chicago
Scientific career
Institutions	Purple Mountain Observatory National Central University

Zhang Yuzhe
Traditional Chinese	Trương ngọc triết
Simplified Chinese	Trương ngọc triết
Transcriptions Standard Mandarin Hanyu Pinyin Zhāng Yùzhé Wade–Giles Chang Yü-che IPA [ʈʂáŋ ŷʈʂɤ̌] Southern Min Tâi-lô Tiunn Gio̍k-tiat

Biography

Zhang was born inFuzhouin theMinhou county,Fu gian provincein 1902. In 1919, he gained entrance toTsinghua University.Graduating in 1923, he traveled to the United States where he began graduate studies at theUniversity of Chicagoin 1925, receiving his Ph.D. in 1929. Later that year, he returned toChinaand accepted a teaching post at theNational Central UniversityinNanjing, China(now known asNanjing University). He was the first astronomy professor atNational Central University.

Zhang wrote his thesis on the orientation of the orbital plane of double stars under the mentorship ofGeorge Van Biesbroeck.While pursuing his Ph.D. at the University of Chicago, in 1928, Zhang discovered anasteroidwhich was given the provisional designation 1928 UF and later the number 1125. He named it "China" or "Trung Hoa" (Zhōnghuá). However, this asteroid was "lost" as it was not observed beyond its initial appearance and a precise orbit could not be calculated (seelost asteroids). In 1957, while Zhang was director of thePurple Mountain Observatoryin China, the observatory discovered a new asteroid. With his agreement the new object1957 UN₁was reassigned the official designation1125 Chinain place of the lost 1928 UF. However, in 1986, the newly discovered object1986 QK₁was confirmed to be a rediscovery of the original 1928 UF, and this object was named3789 Zhongguo( "Trung Quốc" (Zhōngguó) is theMandarin Chineseword for "China", inpinyintransliteration, whereasZhōnghuáis a slightlyolder word for "China").

From 1941 to 1950, Zhang was head of the astronomy research institute atNational Central University.Between 1946 and 1948, he returned to the United States to studyvariable stars.In 1950 Zhang became the director of the Purple Mountain Observatory, a position he held until 1984.

In 1955 he was elected a founding academician of theChinese Academy of Sciences.

Zhang devoted himself to observing and calculating the orbits of minor planets and comets. Many asteroids were discovered at Purple Mountain Observatory, as well as three new comets: two periodic,60P/Tsuchinshan(Tsuchinshan 2) and62P/Tsuchinshan(Tsuchinshan 1), and one non-periodic,C/1977 V1.Tsuchinshanis theWade-Gilestransliteration corresponding to thepinyinZĭjīn Shān,which isMandarin Chinesefor "Purple Mountain", named after the observatory he oversaw.

Asteroidsdiscovered: 1 

3789 Zhongguo

October 25, 1928

MPC

The lunar craterZhang Yuzheand the main-belt asteroid2051 Changare named after him.