MORGAN, HERBERT ROLLO

(b. Medford, Minnesota, 21 March 1875; d. Washington, D.C., 11 June 1957)

astronomy.

Morgan was the son of Henry D. and Olive Sabre Smith Morgan. He received the B.A. from the University of Virginia in 1899 and the Ph.D. in 1901. On 25 May 1904 he married Fannie Evelyn Wallis; they had one daughter. Morgan was a member of the American Astronomical Society (vice-president 1940–1942), American Geophysical Union, International Astronomical Union, American Association for the Advancement of Science (vice-president 1935–1936), and the Washington Academy of Science. He was president of the Commission on Meridian Astronomy of the International Astronomical Union from 1938 to 1948 and associate editor of Astronomical Journal from 1942 to 1948. He received the Watson Medal of the National Academy of Sciences in 1952 for his achievements in fundamental astronomy.

AS a child Morgan suffered from an asthmatic condition, and at the age of nine to avoid the rigors of Minnesota winters his mother took him to Tennessee. He obtained his early education in a country school there whenever his bouts with asthma allowed him to attend. This intermittent schooling was supplemented by instruction at home under the guidance of his mother. When Morgan entered the University of Virginia, his primary interests were mathematics and astronomy. After one year, however, he had to withdraw in order to support his mother, who was growing old. At the university he had met Ormond Stone, director of the Leander McCormick Observatory. Stone took an interest in Morgan and helped him to obtain a Vanderbilt fellowship at the observatory. Stone’s was probably the most important single influence in directing Morgan’s interest toward classical astronomy.

With the aid of the fellowship, Morgan resumed his studies in 1896 and went on to receive the Ph.D. in 1901. During his last year of graduate study he taught mathematics at Pantops Academy, Charlottesville, Virginia, until receiving an appointment as a calculator at the U.S. Naval Observatory in Washington from 1901 to 1905. In 1905 he accepted an appointment as professor of astronomy and mathematics at Pritchett College, Glasgow, Missouri, and director of the Morrison Observatory. In 1907 he returned to the U.S. Naval Observatory, where he remained for the rest of his career. He started as an assistant astronomer on the staff of the nine-inch transit circle and by 1913 was in charge. For the next thirty-one years Morgan carried out a series of fundamental observations of the sun, moon, planets, and selected stars with this instrument. The resulting catalogs are milestones in fundamental astronomy and demonstrate Morgan’s outstanding ability to analyze observations.

Morgan’s earliest scientific papers dealt with the orbits of comets and asteroids. As the precise obser-vations obtained with the nine-inch transit circle ac-cumulated, Morgan turned his attention to the analysis of these observations and those from other observ-atories to obtain information on some of the fundamental constants on which astronomy is built. These analyses led to an extensive series of papers dealing with the position and motion of the equinox, the elements of the principal planets and their varia-tions, and the constants of nutation and aberration. Although he formally retired in 1944, Morgan continued to work voluntarily at the U.S. Naval Observatory on his research, from 1947 to 1950 as a research associate under the auspices of Yale University.

It was during this period that Morgan produced what may be considered his most important work, “Catalog of 5,268 Standard Stars, 1950.0 Based on the Normal System N30.” The N30 catalog is probably the most accurate source of positions and proper motions available today. It proved so useful in the interpretation of problems involving both astrophysical and astrometric data that Morgan was besieged with requests to extend the N30 proper motion system to a larger group of stars. Until several months before his death, he was engaged in deriving the proper motions on the N30 system of several hundred O- and B-type stars.

BIBLIOGRAPHY

Morgan’s writings include “Results of Observations with the Nine-Inch Transit Circle, 1903–1911,” in Publications of the United States Nacal Observatory, 2nd ser., 9 , pt. 1 (1920), 1–452; “Observations made with the Nine-Inch Transit Circle, 1912–1913,” ibid., pt. 4 (1918), 1.-116; “Results of Observations with the Nine-Inch Transit Circle, 1913–1926: Observations of the Sun, Moon, and Planets: Catalogue of 9,989 Standard and Intermediary Stars: Miscellaneous Stars,” ibid., 13 (1933), 1–228; “Results of Observations on the Nine-Inch Transit Circle, 1932–1934: Positions and Proper Motions of 1117 Refer-ence Stars in Declination -10° to -20°: Miscellaneous Stars,” ibid., 14 , pt. 2 (1938), 81–125; “Vertical Circle Observations made with the Five-Inch Alt-Azimuth Instrument, 1916–1933: Catalog of Declinations of Stan-dard Stars: Declinations of the Sun, Mercury and Venus,” ibid., pt. 3 (1938), 127–216; “Proper Motions of 2916 Intermediary Stars, Mostly in Declination -5° to -30°,” ibid., pt. 4 (1938), 217–283; “Results of Observations made with the Nine-Inch Transit Circle, 1935–1945: Observa-tions of the Sun and Planets: Catalog of 5446 Stars: Corrections to GC and FK3,” ibid., 15 , pt. 5 (1948), 115–390; and “Catalog of 5,268 Standard Stars, 1950.0 based on the Normal System N30,” which is Astronomical Papers of the American Ephemeris, 13 , pt. 3 (1952).

Raynor L. Duncombe