Earle B. Mayfield (1923–2007)

Earle B. Mayfield passed away peacefully in his sleep 28 May 2007 in Los Osos, near San Luis Obispo. He retired there to grow orchids, make wine and teach part-time at California Polytechnic University, San Luis Obispo (Cal Poly SLO). He was born in Oklahoma City in 1923. After his discharge from the Coast Guard he went to UCLA where he graduated in physics in 1950. He married Peggy Masterson in 1952 after they met while they both worked at the China Lake Test Station. He obtained a Ph.D. in physics in 1959 from the University of Utah. He is survived by his wife, seven children and 14 grandchildren.

In 1960 Mayfield joined The Aerospace Corporation where he became a strong proponent of expanding the Corporation’s activities in solar research. In 1966, with Mayfield’s support, observations of supergranulation were obtained from Thule, Greenland, that spanned nearly 62 hours of continuous coverage: the longest continuous solar observations at that time.

He was instrumental in the effort to design and construct an advanced 24-inch aperture vacuum solar telescope. The resulting diffraction limited image had an un-vignetted field-of-view of about 0.8 R_e. An auxiliary 11-inch vacuum telescope was available for full-disk observations. Both telescopes were F/20 with reflecting surfaces having proprietary overcoated silver. At the Coude focus was a vacuum spectroheliograph. It was determined that a peninsula jutting out into the Upper Van Norman Reservoir provided superior seeing conditions that was the site of an U.S. Air Force Air Weather Service station. This became the San Fernando Observatory, which was dedicated in February 1969 just before an ad hoc meeting of the Solar Physics Division in Pasadena. Mayfield was its first director.

In 1971, under Mayfield’s direction, Aerospace developed the first digital video magnetograph supported by a NASA grant. This provided real-time magnetograms of solar active regions.

In 1973, James Underwood came to Aerospace and the Aerospace solar group became collaborators in the S-056 X-ray telescope experiment onboard Skylab. The flight films from the S-056 experiment were developed by the Aerospace solar group’s photographic team. The 24-inch vacuum telescope was used extensively in support of the S-056 experiment.

When stable external funding failed to materialize, Aerospace closed the observatory in the summer of 1975 and donated the facility to California State University, Northridge in 1976 with the help of Paul Richter.

Mayfield retired from the Aerospace Corporation in 1985 and moved to Los Osos. He became an adjunct professor at Cal Poly SLO and helped with student projects in the Physics Department. One of his projects involved the design and construction of a solar spectrograph for studying the Zeeman effect in sunspots.

In the early 1970s, Mayfield and Bob Leighton of Caltech organized a series of informal meetings that came to be called the Local Group to advance communication among solar astronomers in Southern California. Mayfield's leadership in solar physics extended not only to building new facilities, instruments, and doing cutting-edge science, he also aided the careers of many students and other solar physicists.