Hale, George Ellery

US astronomer. He made pioneer studies of the Sun and founded three major observatories. In 1889 he invented the spectroheliograph, a device for photographing the Sun at particular wavelengths. In 1917 he established on Mount Wilson, California, a 2.5-m/100-in reflector, the world's largest telescope until superseded in 1948 by the 5-m/200-in reflector on Mount Palomar, which Hale had planned just before he died.

He, more than any other, was responsible for the development of observational astrophysics in the USA. He also founded the Yerkes Observatory in Williams Bay, Wisconsin, in 1897, with the largest refractor, 102 cm/40 in, ever built at that time.