George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer.
Hale was born in Chicago, Illinois. He was educated at MIT, at the Observatory of Harvard College, (1889–90), and at Berlin (1893–94). As an undergraduate at MIT, he is known for inventing the spectroheliograph, with which he made his discovery of solar vortices. In 1908 at Mount Wilson, he used the Zeeman effect with a modified spectroheliograph to establish that sunspots were magnetic. Subsequent work demonstrated a strong tendency for east-west alignment of magnetic polarities in sunspots, with mirror symmetry across the solar equator; and that the polarity in each hemisphere switched orientation from one sunspot cycle to the next. This systematic property of sunspot magnetic fields is now commonly referred to as the "Hale-Nicholson law," or in many cases simply "Hale's law."
In 1890, he was appointed director of the Kenwood Astrophysical Observatory; he was professor of Astrophysics at Beloit College (1891–93); associate professor at the University of Chicago until 1897, and full professor (1897–1905). He was co-editor of Astronomy and Astrophysics, 1892–95, and after 1895 editor of the Astrophysical Journal. He also served on the board of trustees for Science Service, now known as Society for Science & the Public, from 1921-1923.
Hale was a driven individual who worked to found a number of significant astronomical observatories, including Yerkes Observatory, Mount Wilson Observatory, Palomar Observatory, and the Hale Solar Laboratory. At Mount Wilson, he hired and encouraged Harlow Shapley and Edwin Hubble toward some of the most significant discoveries of the time. He was a prolific organizer who helped create a number of astronomical institutions, societies and journals. Hale also played a central role in developing the California Institute of Technology into a leading research university. After retiring as director at Mount Wilson, he built the Hale Solar Laboratory in Pasadena, California, as his office and workshop, pursuing his interest in the sun.
Prof. Hale was elected an honorary fellow of the Astronomical and Physical Society of Toronto in 1899.