Alfred Harrison Joy

Alfred Harrison Joy was an astronomer who lived from September 23, 1882, to April 18, 1973. He was born in Greenville, Illinois and passed away in Pasadena, California. Joy is best remembered for his important studies about how far stars are from Earth, how stars move, and stars that change in brightness over time.

His work helped scientists understand the universe better. Because of his contributions, a crater on the Moon was named after him, a special way to honor someone who did great work in science.

Early years

Alfred Harrison Joy was born in Greenville, Illinois. His father, F.P. Joy, was a well-known clothing merchant and even served as the town’s mayor. Alfred went to school at Greenville College and graduated with a BA in 1903. The next year, he earned an MA from Oberlin College.

Career

After finishing his studies, Joy taught astronomy and led the observatory at the American University of Beirut. He had to leave in 1915 because of World War I.

Later, he joined the Mount Wilson Observatory in the United States, where he worked until 1952. There, he helped figure out important details about more than 5,000 stars, like their types, distances, and how they move. He also studied how stars’ light changes to learn about their sizes and movements. In 1950, he received the Bruce Medal for his work. He also served as president of the Astronomical Society of the Pacific in 1931 and 1939.