Richard Irwin Mitchell, astronomer and mathematician, passed away on 5 February 1990, in Albuquerque, New Mexico, after a long illness. He was the only child of Lawrence C. Mitchell and Helen (nèe Thompson) Mitchell and was born in Oakland, California on 1 February 1927. He went to Frick Jr. High and Fremont High School, both in Oakland. After graduating early from high school, Mitchell enlisted in the US Navy. He was discharged in 1946 as Electronics Technicians Mate Second Class.
On 22 December 1950 Mitchell married Mary E. Lundquist, now deceased, and they are survived by four children, Leslie Louise Senghaas, Mark Richard Mitchell, Gail Elizabeth Scott, and David Lawrence Mitchell, and four grandchildren.
Dick, as most of us knew him, received a BA in Physics in 1950 and an MA in Astronomy in 1955 both from the University of California at Berkeley (UCB). Later in 1955 he started his professional career in astronomy at the Lowell Observatory where he began an association with Harold L. Johnson that spanned more than 20 years of scientific research. As a result of his friendship and long association with Johnson, Dick collaborated in publishing over 30 astronomical papers covering many of the major fields of astronomy, particularly the fields of photometry of stellar clusters, infrared observations, and, more recently, photometry of bright stars. Dick was at the Lowell Observatory from 1955 to 1959, at the Department of Astronomy, University of Texas (UT), from 1959 to 1962, at the University of Arizona (Lunar and Planetary Laboratory from 1962 to 1969, and the Optical Sciences Center from 1969 to 1971), and at the McDonald Observatory, UT, from 1971 to 1974. Because of his expertise in astronomy and data processing, Dick was frequently called upon to teach university courses in astronomy, the physical sciences, and computer science, and did so at UCB, UT, and the National University of San Diego. At UT Dick also taught a graduate course in statistical astronomy with an introduction to computer programming fundamentals.
Throughout his career Dick was involved in a number of large astronomical research projects as an observer, as coordinator and supervisor, as teacher, and as data manager and computer programmer. He assisted with the creation of several stellar photometric systems. While working at the University of Arizona, Dick developed computer data reduction programs for UBVRI, 13- color, and infrared photometry. Those programs have received considerable use at a number of astronomical centers in the United States, México and Chile.
Dick had a long friendship and association with Mexican astronomers and astronomy. He was co-author, with Johnson, Braulio Iriarte and Wieslaw Wisniewski, of the ‘‘Arizona-Tonantzintla Catalogue: Magnitudes and Colors of 1,325 Bright Stars’’ (Sky & Telescope 30, 21-31, 1965). From 1974 to 1978, Dick worked at the Centro de Investigación Cientifica y Educación Superior de Ensenada, Baja California, México, as an assistant professor and manager of the computing center. Under his supervision and direction this center grew into a full department of computer science. When he left in 1978, this department was completely managed and staffed by Mexican personnel, many of whom were previous students of Dick. While in Ensenada, Dick also served as an adviser for a number of astronomical projects at the Observatorio Astronómico Nacional at San Pedro Mártir. Dick was always a very good friend to students and astronomers from the Mexican universities and observatories. He was always patient and available with ideas, advice, and encouragement. Over the years he was an acknowledged mentor to several PhD and MS theses.
Dick’s help and encouragement were the key to my finishing quickly and thoroughly a PhD dissertation at the University of Arizona. He always regretted not having obtained a PhD himself, due mainly to his inability to master a foreign language.
After 1978, Dick worked for the BDM Corporation and was involved mostly with the management and computer programming for various government projects. However, he never lost his strong interest in astronomy. During 1983-1984 he participated as Adjunct Lecturer in the Senior Advanced Seminar in Astrophysics at the University of Nevada, Las Vegas. In 1985, Dick published one of his last papers, ‘‘Solar Colors on the 13-Color System,’’ in the Astronomical Journal (Volume 90, p.2116). In October 1989, Dick realized that the end was near and donated his personal computing facilities for the reduction of astronomical images, and his extensive collection of scientific books and journals to the Observatorio Astrofísico Guillermo Haro at Cananea, Sonora, México. A significant part of that observatory’s library is still that portion donated by Dick. To the end Dick Mitchell cared about and helped others. He will be missed!