Grossmann, Ernst A. F. W.

(b. Rothenburg, near Bremen, Germany, 16 February 1863; d. Munich, Germany, 17 March 1933)

astronomy.

Grossmann began to study astronomy in 1884 at Göttingen, where he took his doctorate under A. C. W. Schur and Leopold Ambronn in 1891. He was assistant at the Göttingen observatory from 1891 to 1896, at Moritz Kuffner’s observatory in Vienna from 1896 to 1898, at the Leipzig observatory from 1898 to 1902, and at the Kiel observatory from 1902 to 1905. In 1905 he became observer at Munich, where he lived for the rest of his life. He retired in 1928.

Grossmann was an enthusiastic and important worker with meridian instruments. All of his work was devoted to questions concerning fundamental astrometric measurements. After examining systematic errors in measurements of double stars in his dissertation, he made careful observations with the meridian circles of all the observatories where he worked. One main area of his research was the theory of atmospheric refraction; his very important examination of existing observations resulted in a value for the constant of refraction of 60.15”, which is still used.

Grossmann’s observations of fundamental right ascensions near the celestial pole indicated clearly that the values adopted at that time were affected by systematic errors. Although his attempts to measure stellar parallaxes by a meridian circle were unsuccessful, they convinced astronomers that the photographic method is better. In 1921 he showed that existing observations of the planet Mercury were not sufficiently accurate to permit determination of a reliable value of the relativistic motion of its perihelion. It was more than twenty years later that a new comprehensive discussion of all observations of Mercury made between 1765 and 1937, which was undertaken by the U.S. Naval Observatory at Washington, showed convincingly that the observed value of the motion of perihelion was in agreement with the theory of relativity.

BIBLIOGRAPHY

Grossmann’s major works, are “Untersuchungen über die astronomische Refraktion,” in Abhandlungen der K. Bayerischen Akademie der Wissenschaften, Math,-phys. Kl., 28 , no. 9 (1917), 1–72; “Die Bewegung des Merkurperihels nach den Arbeiten Newcombs,” in Astronomische Nachrichten, 214 (1921), 41-54 ; and “Parallaxenbestimmungen am Meridiankreise,” in Neue Annalen der K. Sternwarte in München, 5 , no. 1 (1926), 1–173.

There is no secondary literature.

F. Schmeidler