Albrecht Otto Johannes Unsöld

Albrecht Otto Johannes Unsöld


Date of Birth
April 20, 1905
Date of Death
September 23, 1995

Albrecht Unsöld studied quantum mechanics under Arnold Sommerfeld at the University of Munich and began working on stellar atmospheres in 1927. He spent nearly his entire career at Kiel University, where he was appointed professor in 1932. By intensive study of the processes influencing the formation and shape of spectral lines — the effects of abundances, radiation damping, Doppler shifts, electric fields, and collisions — he greatly improved the methods of determining physical conditions in stellar atmospheres. Unsöld's analysis of the spectrum of the B0 star Tau Scorpii, obtained on a 1939 visit to Yerkes and McDonald Observatories, provided the first detailed analysis of a star other than the sun. From it he determined the physics and composition of the star’s atmosphere. He wrote an influential book on stellar atmospheres, edited the Zeitschrift für Astrophysik until it was merged with other European journals into Astronomy and Astrophysics, and educated many important astronomers.

Presentation of Bruce medal

Wilson, O.C., PASP 68, 89-91 (1956).

Other awards

Royal Astronomical Society, Gold medal, 1957, presented by H. Jeffreys, MNRAS 117, 344-46 (1957)

Some offices held

Astronomische Gesellschaft, President, 1947-48.

Biographical materials

Modern Scientists and Engineers (McGraw-Hill, NY, 1980).
Theis, Christian, Biographical Encylopedia of Astronomers, 2nd ed., 2014 (Springer), pp. 2197-99. Wiedemann, Volker, Kiel University


Baschek, Bodo, Mitteilungen der Astronomische Gesellschaft 79, 11-15, (1996) [in German].
Seaton, Mike, Astronomy & Geophysics 38, 1, 37-38 (1997).
Wiedemann, Volker, PASP 108, 553-55 (1996).


AIP Center for History of Physics

Named after him

Minor planet #2842 Unsöld


Papers, etc.

Unsöld’s papers are at Kiel University. There is a manuscript autobiography at the AIP Center for History of Physics, along with oral history interviews recorded in 1978 and 1984.

Other References: Historical

Search ADS for works about Unsöld

Baschek, Bodo, Wilhelm H. Kegel, & G. Traving, eds., Problems in Stellar Atmospheres and Envelopes: Dedicated to Albrecht Unsöld on the occasion of his seventieth birthday (Springer-Verlag, Berlin, NY, 1975).

Baschek, Bodo, “Talk in Honor of Albrecht Unsöld’s 100th Anniversary: Physics of Stellar Atmospheres—New Aspects of Old Problems,” in Siegfried Roeser, ed., Reviews in Modern Astronomy 19: The Many Facets of the Universe - Revelations by New Instruments. International Scientific Conference of the Society held at Koeln, Germany, September 25 - October 1, 2005 (Wiley-VCH Verlag, Wenheim, Germany, 2006), pp. 61-74.

Baschek, Bodo, “Physics of Stellar Atmospheres—New Aspects and Old Problems,” in G. Wolfschmidt, ed., Entwicklung der theoretischen Astrophysik Nuncius Hamburgensis. (Tredition, Hamburg, Germany, 2011), pp. 383-97.

Hearnshaw, John B., The Analysis of Starlight (Cambridge University Press, Cambridge, UK, 1986).

Kuiper, Gerard P., “German Astronomy During the War,” Popular Astronomy 54, 263-87 (1946).

Schmidt-Schonbeck, Charlotte, Dreihundert Jahre Physik und Astronomie an der Kieler Universitat (F. Hirt, Kiel,1965).

Strömgren, Bengt, “On the Chemical Composition of the Solar Atmosphere,” Festschrift für Elis Strömgren (Eina Munksgaard, Copenhagen, 1940), pp. 218-57.

Unsöld, A., “Introduction: A Fifty Years Retrospect,” in The Elements and their Isotopes in the Universe; Twenty-second International Conference on Astrophysics, Liege, Belgium, June 20-22, 1978 (Universite de Liege, Belgium, 1979), pp. 7-21.

Weidemann, V., 2011. Albrecht Unsöld – Biographie und Briefwechsel. In in G. Wolfschmidt, ed., Entwicklung der theoretischen Astrophysik Nuncius Hamburgensis. (Tredition, Hamburg, Germany, 2011), pp. 357-78.

Wielebinski, Richard, “Albrecht Unsöld: a Pioneer in the Interpretation of the Origin of the Cosmic Radio Emission,” Journal of Astronomical History and Heritage 16, 67-80 (2013).


Other References: Scientific

Search ADS for works by Unsöld

Unsöld, Albrecht, Physik der Sternatmosphären, mit besonderer Berücksichtigung der Sonne (Springer-Verlag, Berlin, 1938, 1955, 1968).

Unsöld, Albrecht, “Quantitative Spektralanalyse des B0-Sternes τ Scorpii,” Zeitschrift für Astrophysik 21 1-21 (1941); 21, 22-84 (1941); 21, 229-48 (1941); and 23, 75-97 (1944) [A portion of the second paper in this series is translated and reprinted, with commentary, in Lang, Kenneth R. & Owen Gingerich, eds., A Source Book in Astronomy & Astrophysics, 1900-1975 (Harvard Univ. Press, Cambridge, MA, 1979), 268-74.]

Unsöld, Albrecht, Der Neue Kosmos (1967, 1974); translation: The New Cosmos (Springer-Verlag, Berlin, NY, 1969, 1977).

Unsöld, Albrecht, Physik der Sternatmosphaeren mit besonderer Beruecksichtigung der Sonne (J. Springer, Berlin, NY, 1968).

Unsöld, Albrecht O.J., “Stellar Abundances and the Origin of the Elements,” Science 163, 1015-25 (1969).

Unsöld, A., “Abundance Distributions and Origin of the Elements,” Naturwissenschaften 63, 443-48 (1976).

Unsöld, Albrecht, “Introduction: A Fifty Years Retrospect,” in The Elements and Their Isotopes in the Universe; International Conference on Astrophysics, 22nd, Liege, Belgium (Universite de Liege, 1979), pp. 7-21.

Unsöld, Albrecht & Bodo Baschek, Der Neue Kosmos (Springer-Verlag, Berlin, 1981, 1988, 1999, 2002); translation: The New Cosmos (Springer-Verlag, Berlin, NY, 1983, 1991, 2001).

Unsöld, A., Evolution Kosmischer, Biologischer und Geistiger Strukturen (Wissenschaftliche Verlagsgesellschaft, Stuttgart, 1981).


Other Works: Popularizations, History, etc.

Unsöld, Albrecht, “The Astronomical Outlook in Germany,” Popular Astronomy 57, 107-10 (1949).

Unsöld, Albrecht, Stellar Abundances and the Origin of the Elements ASP Leaflets 10, 321-28 (1970) [Leaflet #491] and 10, 329-36 (1970) [Leaflet #492]

Unsöld, Albrecht, Sterne und Menschen (Springer-Verlag, Berlin, 1972).

Struve, O., A. Unsöld, C.T Elvey, & A.S. Eddington, “Interstellar Gas,” Sci. Amer. 245, 10 (1981).

Unsöld, A. “Kosmische Häufigkeitsverteilung und Entstehung der chemischen Elemente,” Nova Acta Leopoldina 47, 107-10 (1977).

Unsöld, A. “Die Evolution physikalischer Ideen seit der Renaissance, ”Naturwiss. Rundsch. 30, 117-22 (1977).

Unsöld, A. “Strukturen des Denkens, ”Naturwiss. Rundsch. 31, 309-15 (1978).

Unsöld, Albrecht, Evolution kosmischer, biologischer und geistiger Strukturen (Wissenschaftliche Verlagsgesellschaft, Stuttgart, 1981).

Unsöld, A. “Zum 100. Geburtstag von Sir A. S. Eddington,” Mitteilungen der Astronomischen Gesellschaft 60, 17-18 (1983).