Alumni: Yu Che Chang, 1929
Ph.D., University of Chicago, 1929

16 February 1902 - 21 July 1986


Zhang Yuzhe (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 curves of asteroids, and thus their rotation periods. He also researched the variable star CZ Cassiopeiae and the evolution of the orbit of Comet Halley. Zhang discovered 3 comets and is credited under the name Y. C. Chang by the Minor Planet Center for the discovery of one minor planet, the outer main-belt asteroid 3789 Zhongguo.

Zhang was born in Minhou, Fujian province in 1902. In 1919, he gained entrance to Tsinghua University. Graduating in 1923, he traveled to the United States where he began graduate studies at the University of Chicago in 1925, receiving his Ph.D. in 1929. Later that year, he returned to China and accepted a teaching post at the National Central University in Nanjing, China (now known as Nanjing University).
From 1941 to 1950, Zhang was head of the astronomy research institute at National Central University. Between 1946 and 1948, he returned to the United States to study variable stars. In 1950 Zhang became the director of the Purple Mountain Observatory, a position he held until 1984.

The lunar crater Zhang Yuzhe and the main-belt asteroid 2051 Chang are named after him.