Obituary

Eugenio E. Mendoza Villareal 1927-2019

On October 21, 2019, the Mexican astronomical community mourned the loss of Dr. Eugenio Emilio Mendoza Villareal, a pioneering astronomer. He was 92 years old.

Eugenio was born in Mexico City on August 19, 1927. As a young student at the Escuela Nacional Preparatoria No. 1, Eugenio eagerly learned mathematics and astronomy. In 1949 he entered the Science Faculty of the Universidad Nacional Autónoma de México (UNAM) where he obtained his Bachelor’s degree in 1952. Soon thereafter, he was recruited by Guillermo Haro and Paris Pismis, of the National Astronomical Observatory, as a promising candidate to be supported and sent to the USA to pursue a doctorate program in astronomy at a top university. In Tonantzintla he had already met W. W. Morgan, of the University of Chicago, and there he went to obtain his theoretical, spectroscopic and photometric training under W. W. Morgan himself, and also under S. Chandrasekhar and B. Strömgren. He completed his Ph.D. in 1957. After spending a year in Cambridge, England, working with Fred Hoyle, he returned to Mexico in 1958, as the second Mexican astronomer to hold a Ph.D.

At the Astronomy Institute, UNAM, he developed his training and became an acute observer. In the early sixties he undertook the task of searching for a proper site to install the new telescopes of the National Observatory. He is remembered as trekking and camping in the Sierra de San Pedro Mártir, in Northern Baja California, on mule-back, carrying scientific equipment. He found the place where the San Pedro Mártir Observatory stands today. Eugenio acted as the chief of the Observatory from 1970-1972.

Eugenio’s astronomical fields of interest were broad, and his contributions were outstanding. Worth mentioning are his discovery of infrared excesses in T Tauri and FU Orionis stars (ApJ 143, 1010, 1966; ApJ 151, 977, 1968), and his infrared observations of V1057 Cyg (BOTT 6, No. 37, 1971; ApJ 169, L117, 1971), which anticipated the discovery of circumstellar disks in pre-main sequence stars.

His design and fabrication of narrow band filters centered on the luminosity-sensitive triplet OI 7774 provided a spectrophotometric measure of the stellar luminosity, and hence of the distance of individual luminous stars, as well as a calibration tool to be used for cosmic distance measurements.

As a well deserved recognition of his work, in 1967 he received the National Prize of Science of the Academia Mexicana de la Investigación Científica. In 1987 he was awarded the UNAM Prize in Exact Sciences.

From 1973 to 1977 he acted as one of the founding editors of the Revista Mexicana de Astronomía y Astrofísica, RMxAA.

He retired in 1993. During that year, the Institute of Astronomy held an international Symposium to honor him (RMxAC, Vol. 29, 1993). In 2016 the International School of Observational Astronomy for Latin American Students, at the Tonantzintla Observatory, was held in his honor.

Over nearly four decades he guided and counselled many students, thus establishing a foundation for future generations of astronomers. Those who had the fortune to interact with him were enriched by his expertise and wise guidance; they discovered, behind a rather austere personality, a warm, joyful and friendly person, interested in the problems of his colleagues and always willing to help. I benefitted from Eugenio’s good advice and example to decide and find my own professional destiny. I am proud to be a co-author of his last two astronomical papers.

Dr. Eugenio Mendoza is survived by his daughter, Xochiquetzal, and his son, Tonatiuh. Several generations of Mexican astronomers shall remember him thankfully as one of the founders of modern Mexican astronomy.