Hufnagel, Leon

(b. Warsaw Poland, 1893; d Berlin, Germany, 19 February 1933)

astronomy.

Hufnagel entered the faculty of mathematics and physics of Warsaw University in 1911. After receiving the Ph.D. at Vienna in 1919, he retuned to Poland, serving as an assistant at the Free University, Warsaw, in 1921–1926. In the latter year he left Poland for Sweden, where he worked at Lund Observatory in 1926–1928. For the next two years he was Rockefeller traveling fellow at the Mt. Wilson, LIck, and Harvard College observatories. From 1930 he worked at the Astronomisches Recheninstitut, Berlin-Dahlem, and the astrophysical observatory, Potsdam.

Hufnagel’s first scientific papers were in celestial mechanics. In 1919 he determined the orbit of the great September comet (1882 II), and with J. Krasowski he calculated the perturbations of the asteroid (43) Ariadne in 1925. After 1925 his major scientific work concerned stellar statistics and astrophysics. His first paper on proper motions of stars was published at Warsaw in 1925, but the most important ones were written during his two years at Lund and in Germany after 1930. In seven papers published in 1926–1933 Hufnagel considred the velocity distrbutions of faint stars and the influence on such distributions of accidental errors in proper motions. He cooperated on studies of this problem with K. G Malmquist in 1933 and with F. Gondolatsch in 1931. During his stay in the United States, Hufnagel published two papers on stellar temperature and one note on galactic rotaion (1929). With B. P. Gerasimovich, at the Harvard College Observatory, he investigated the semiregular variable star R Sagittae (1929). His last scientific paper, written with H. Müller (1935), converned the asborption by interstellar clouds near the North America nebula. Hufnagel’s main work in the last two years of his was the elaboration of the first two chapters (“Grundlagen dermathematischen Statistik”) of Lehrbuch der Stellarstatistik, edited by E. von der Pahlen (Leipzig, 1937).

BIBLIOGRAPHY

I. Original Works. Hufnagel’s papers include “Die Bahn der grossen September Kometen 1882II under Zugrundelegung der Einsteinschen Gravitationslehrre,” in Sitzungsberichte der Akademie der Wissenschafien in Wien, 128 (1919), 1261–1270; “Sur les mouvements propres desétoiles,” in Bibliotheca Universtitatis Librae Polonae, 13 , fasc. A (1924); “Perturbations et tables approchées du mouvement de la petite planète (43) Ariadne,” ibid., 14 (1925), written with J. Krassowski: “Über eine Formel der Stellarstatistik,” in Astronomische Nachrichten, 228 (1926), 321–324; “Zur Geschwindigkeitsverteilung schwacher Sterne,” ibid., 231 (1927), 297–304, and 242 (1931), 385–392, written with F. Gondolatsch; “Über die Räumliche Geschwindigkeitsverteilung der Sterne zwischen 9, und 14. Grösse,” in Meddelanden från Lunds astronomiska observatorium, 2nd ser., vol. 5 (1927); “On the Influence of the Accidental Errors in the Proper Motions on the Velocity Distribution,” ibid., no. 114 (1928); “Über den Einfluss zufälliger und systematischer Fehler auf das Geschwin-digkeitsellipsoid,” ibid., no. 123 (1930); “Note on the Galactic Rotation,” in Bulletin. Astronomical Observatory, Harvard University, vol. 863 (1929); “Temperatures of Giants and Dwarfs,” in Circular, Astronomical Observatory of Harvard Colloge, vol. 343 (1929); “Note on Stellar Temperatures,” in Bulletin, Astronomical Observatory, Harvard University, vol. 874 (1930); “The Distribution in Space of the Stars of Type A as Derived From the Draper Catalogue,” in Astronomiska Iakttagelser och Undersökningar på Stockholms Observatorium, vol. 11 , no. 9 (1933); and “Untersuchungen über absorbierende Wolken beim Nordamerika Nobel unter Benutzung von Farbenindizes schwacher Sterne,” in Zeitscjroft für Astrophysik,, 9 (1935), 331–381, written with H. Müller.

II. Secondary Literature. Obituaries are in Astronomische Nachrichten, 248 (1933), 143; and Monthly Notices of the Royal Astronomical Society, 94 (1933), 276–277.

Eugeniusz Rybka