James Arthur Hughes (1929–1992)

After being hospitalized briefly, James A. Hughes died of cancer on January 15th, 1992. A persistent cough that developed during the late summer of 1991 was finally diagnosed as esophageal cancer. Although feeling the effects of his illness, he continued his work until December 10th and was hospitalized at the end of the month. His professional career was spent at the U.S. Naval Observatory in Washington D.C. where he was not only one of the most distinguished members of the staff but also an accessible and very popular person who was known to most as "Jim."

Jim Hughes was born in Sharon, Pennsylvania on June 10, 1929. After growing up in Sharon, Jim served in the Air Force for three years where he was a member of the Air Force Band. He next attended Columbia University, graduating with a BA in 1957. Jim was hired as an astronomer by the Naval Observatory in November 1959 and was the one of the first employees to take part in the Professional Development Program. This led to a PhD from Columbia in 1966. Jim loved music and participated actively in it throughout his life. At the time of his death he was a percussionist in the Rockville (Maryland) Band.

During his career at the U.S. Naval Observatory, Jim compiled a distinguished record that included substantial contributions to every aspect of astrometry. His own personal research greatly advanced the theory and realization of stellar reference frames, astrometric instrumentation, cataloging of stellar positions and motions, and the theory of atmospheric refraction. Finally, he oversaw significant progress in the areas of double star astrometry ( Washington Double Star Catalog) and photographic astrometry ( USNO Northern Astrographic Catalog), and he directed the efforts to resume the compilation of fundamental catalogs at the Naval Observatory.

The early part of Jim's career involved contributions in the areas of transit circle programs and catalog compilation. He was responsible for the planning and conduct of the photographic zenith tube star list observing program and for the compilation of the resulting accurate catalog of positions and motions. He next played a principal part in the planning and inception of the observing program at EI Leoncito, Argentina, seeing the project off to a strong start as the first director at the station. Since becoming Director of the USNO's Astrometry Department in 1977, Jim oversaw the northern Dual 8" Astrograph program, the completion of the W6-50 absolute program (transit circle) and he was the driving force behind the establishment of the Pole-to-Pole Fundamental Program at Washington and Black Birch, New Zealand. Under his direction many of the world's best astrometric catalogs were completed, including the Zodiacal Zone Catalog, the Washington Double Star Catalog (1984.5), three Washington absolute catalogs, (W5-50, WL-50 and recompilation of W4-50), the Southern Reference Stars (SRS - in collaboration with the Pulkovo Observatory), the faint portion of the FK5 and the reference star standards: the International Reference Stars (IRS) and the Astrographic Catalog Reference Stars (ACRS). Finally, work on the Washington Fundamental Catalog was begun during his tenure. His contributions to reductions of astrometric observations include a new approach to the computation of apparent places and a method of determining atmospheric refraction that makes more rigorous use of the temperature gradient in the atmosphere.

Instrumental development is another area in which Jim was a productive researcher during his whole career. He was a key participant in the design and installation of the El Leoncito observing system. He designed and oversaw the construction of the image dissector system for the 7" Transit Circle, now in use at Black Birch. His research into the problems of making absolute observations and his foresight in the design of the image dissector have resulted in the 7" Transit Circle being potentially the world's most effective link between the FK5 and the dynamical system due to its success with daytime observations. Concurrent with this work, he directed the very successful effort to obtain a speckle interferometer for the 26" Refractor, which has resulted in greatly improved observations of double stars. The mid-1980's also saw him lead a successful fight to preserve the observing environment of the USNO in Washington DC that resulted in restrictions on development around the Observatory's perimeter.

Jim's greatest accomplishment in instrumentation was his work in optical interferometry. He collaborated in demonstrating the practicality of using active tracking of white light fringes from stellar sources for wide-angle astrometry and developing the concepts of a working instrument. Leading the USNO's part of the collaborative effort to produce a prototype, Jim played a key role in the development of the MARK III, the world's first astrometric interferometer. After that he was the driving force behind the effort to build a dedicated, optical interferometric observatory. That the project is well established and that it promises to deliver positional accuracies comparable to those of the radio frame are two reasons for his reputation as one of the world's leading experts in this field.

In 1985 Jim was appointed as chairman of the IAU Working Group on Reference Frames. This was an unusually large working group with a formidable task. The Working Group was composed of 47 members representing eight IAU Commissions that specialize in such diverse areas as astrometry, galactic structure, radio astronomy, Earth orientation, ephemerides, celestial mechanics and time. Extensive correspondence, several meetings of the Working Group, a major colloquium, two IAU general assemblies and numerous personal contacts were all required for a successful outcome, which was to define the direction that both observation and theory should take in regard to the celestial reference frame. This achievement was realized through: first, a consensus on definitions, relativistic metrics (including time) and observational principles; second, a formal resolution to the IAU that contains nine specific recommendations for implementing the concepts; and third, the organizing and publishing of IAU Colloquium 127 that was attended by many of the top scientists in the world in the fields of astrometry, celestial mechanics and time. The proceedings of this colloquium (1991) contain much of the basis for the conclusions reached by the Working Group and will serve as a reference source on the various subjects for many years. The publication of IAU Colloquium 127 and conclusions reached by the Reference Frames Working Group at the Buenos Aires General Assembly of the IAU constituted the last major work completed by Jim. He was justifiably proud of this accomplishment for it spans all of astrometry and influences a number of other fields as well. Indeed, it is a fitting conclusion to so distinguished a career.

In closing I felt I should speak for the staff of the USNO and mention how highly regarded Jim Hughes was by all who had the pleasure of working with him. He was a very kind person who always gave high priority to those who worked for him. If anyone in the Astrometry Department had a problem, he knew that he could go to Jim and he would do his best to help that person. In the daily routine of work each of us also knew that we could always go to Jim's office to discuss our projects. Many of us probably took too much of his time, but there was always much to learn from him. Each person in the department is glad to have had these opportunities to talk with him, and each of us wishes they had not ended so soon.