RARE "The Joy Crater" Alfred Joy Signed FDC Dated 1948 For Sale

Up For sale a VERY RARE! "The Joy Crater" Alfred Joy Hand Signed First Day Cover Dated 1948

ES-3263

Alfred Harrison Joy (September

23, 1882 in Greenville, Illinois –

April 18, 1973 in Pasadena, California) was

an astronomer best known for his work on stellar distances,

the radial motion of stars, and variable stars. A crater on the moon has been named in his honor. He was

born in Greenville, Illinois, the

son of F.P. Joy, a prominent clothing merchant in Greenville and one-time mayor

of the town. He received a BA from Greenville College in 1903 and an MA

from Oberlin College the

next year. After graduating, Joy went on to work at the American University of

Beirut in the Syrian Protestant College as a professor of

astronomy and the director of the observatory. He was forced to return to the

U.S. in 1915 because of World War I. In the United

States, he worked at the Mount Wilson Observatory from

1915 to 1952. There, he and his colleagues ascertained the spectral type, absolute magnitude, and

stellar distance of over 5,000 stars. Joy also initially defined the T-Tauri type star. He studied the Doppler displacement of the spectral lines of stars to

determine their radial velocities deducing a star's absolute dimensions,

masses, and the orbital elements of some specific stars. He won the Bruce Medal in 1950. He was president of the Astronomical

Society of the Pacific in 1931 and 1939.