Zhang Yuzhe facts for kids

Zhang Yuzhe (born February 16, 1902 – died July 21, 1986), also known as Yu-Che Chang, was a famous Chinese astronomer. He was the director of the Purple Mountain Observatory and is often called the "father of modern Chinese astronomy."

Zhang Yuzhe studied how asteroids reflect light, which helped him figure out how fast they spin. He also looked into a special type of star called a variable star (CZ Cassiopeiae) and tracked the path of Halley's Comet. He discovered three comets and one minor planet (an asteroid) called 3789 Zhongguo. The Minor Planet Center lists his asteroid discovery under the name Y. C. Chang.

Early Life and Education

Zhang Yuzhe was born in 1902 in Minhou, which is in Fujian province, China. In 1919, he was accepted into Tsinghua University, a very good school.

After graduating in 1923, he traveled to the United States. In 1925, he started studying at the University of Chicago. He earned his Ph.D. (a high-level degree) in 1929. Later that year, he went back to China. He became a teacher at the National Central University in Nanjing, China. Today, this university is known as Nanjing University.

Discovering Asteroids

While Zhang was studying at the University of Chicago in 1928, he discovered an asteroid. It was first called 1928 UF and later given the number 1125. He named it "China" or "中華" (Zhōnghuá).

However, this asteroid was "lost." This means astronomers could not find it again after its first sighting. Because of this, they could not figure out its exact path around the Sun.

Years later, in 1957, Zhang was the director of the Purple Mountain Observatory in China. The observatory found a new asteroid. With Zhang's permission, this new object was officially named 1125 China. It took the place of the lost 1928 UF.

But the story doesn't end there! In 1986, another newly found object was confirmed. It turned out to be the original 1928 UF that had been lost! This rediscovered asteroid was then named 3789 Zhongguo. "中国" (Zhōngguó) is the modern Mandarin Chinese word for "China."

Career and Contributions

From 1941 to 1950, Zhang was in charge of the astronomy research institute at National Central University. Between 1946 and 1948, he returned to the United States. There, he continued his studies on variable stars.

In 1950, Zhang became the director of the Purple Mountain Observatory. He held this important position for many years, until 1984. In 1955, he was chosen as one of the first members of the Chinese Academy of Sciences. This is a very high honor for scientists in China.

Zhang Yuzhe spent his life observing and calculating the paths of minor planets and comets. Under his leadership, the Purple Mountain Observatory discovered many asteroids. They also found three new comets. Two of these comets orbit the Sun regularly: 60P/Tsuchinshan and 62P/Tsuchinshan. One comet does not orbit regularly: C/1977 V1. The name Tsuchinshan comes from Zĭjīn Shān, which means "Purple Mountain" in Chinese. This name honors the observatory he led.

Legacy

To honor his great work, a crater on the Moon is named Zhang Yuzhe. Also, an asteroid in the main asteroid belt, 2051 Chang, is named after him.

See also

In Spanish: Zhang Yuzhe para niños