Bengt Georg Daniel Strömgren (21 January 1908 – 4 July 1987) was a
Danish astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...
and
astrophysicist.
Life and career
Bengt Strömgren was born in
Gothenburg
Gothenburg ( ; ) is the List of urban areas in Sweden by population, second-largest city in Sweden, after the capital Stockholm, and the fifth-largest in the Nordic countries. Situated by the Kattegat on the west coast of Sweden, it is the gub ...
. His parents were Hedvig Strömgren (née Lidforss) and
Elis Strömgren, who was professor of
astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...
at the
University of Copenhagen
The University of Copenhagen (, KU) is a public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia, after Uppsala University.
...
and director of the University Observatory in Copenhagen. Bengt grew up in the professor's mansion surrounded with scientists, assistants, observers and guests. His father paced and promoted Bengt into a life with science, and Bengt's first paper was published already at the age of 14. He graduated from high school in 1925 and enrolled at the Copenhagen university. Only two years later, he graduated in astronomy and
atomic physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms. It is primarily concerned wit ...
, and during the following two years, he completed a
doctoral degree
A doctorate (from Latin ''doctor'', meaning "teacher") or doctoral degree is a postgraduate academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' licentia docendi'' ("licence to teach ...
, which was evaluated with the best marks in December 1929, when he was 21 years old.
He gained a great deal of useful experience from his studies in
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...
at
Niels Bohr
Niels Henrik David Bohr (, ; ; 7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and old quantum theory, quantum theory, for which he received the No ...
's Institute close by, and he was at the right place at the right time. He soon found out that he intended to use the fresh theoretical framework of
quantum physics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
in space, and investigate the applications of
quantum mechanics
Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
in stars. Obviously, questions of
nepotism
Nepotism is the act of granting an In-group favoritism, advantage, privilege, or position to Kinship, relatives in an occupation or field. These fields can include business, politics, academia, entertainment, sports, religion or health care. In ...
were in play when he applied for an assistantship already in 1925, which he didn't get. But only one year later it was given to him anyway — he was the best, regardless of his employer being also his own father.
After being appointed as lecturer at the university in 1932, Strömgren was invited to the
University of Chicago
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
in 1936 by
Otto Struve. Going abroad for 18 months meant a lot to the young researcher, and when he went back to
Denmark
Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...
and to the rising
national socialism
Nazism (), formally named National Socialism (NS; , ), is the far-right totalitarian socio-political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Germany. During Hitler's rise to power, it was frequ ...
in
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
, he succeeded his father's professorship in 1940. During five years of isolation, under the
German
German(s) may refer to:
* Germany, the country of the Germans and German things
**Germania (Roman era)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizenship in Germany, see also Ge ...
occupation of Denmark, he initiated the building of a new Danish Observatory, the
Brorfelde Observatory
Brorfelde Observatory (; List of observatory codes, obs. code: IAU code#054, 054) is an astronomy, astronomical observatory located in Brorfelde near Holbæk, Denmark. It is home to the Brorfelde Schmidt Telescope and was run as a branch ...
. But after the
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, Bengt Strömgren became tired of lacking state funding for the project, and with a stagnant national economy, he felt that he had to leave Danish research, which he did in 1951.
He went to the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and became director of the
Yerkes and
McDonald Observatories, and stayed there for six years. In 1957, he was appointed the first professor of theoretical astrophysics at the
Institute for Advanced Study
The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...
in Princeton, where he got
Albert Einstein
Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...
's office. He stayed at Princeton with his family until 1967, when he went back to his homeland Denmark, and became the next to the last resident in a series of great Danish scientists of the
Carlsberg Mansion and Honor, which had earlier been occupied by
Niels Bohr
Niels Henrik David Bohr (, ; ; 7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and old quantum theory, quantum theory, for which he received the No ...
among others. In 1987, he died after a short period of illness.
Science
Bengt Strömgren made momentous contributions to astrophysics. He found that the
chemical
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combin ...
composition of
star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
s was very much different than previously assumed. In the late 1930s, he found the relative abundance of
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
to be nearly 70%, and
helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...
to be about 27%. Just before the war, he discovered the so-called
Strömgren Spheres — huge interstellar shells of ionized hydrogen around stars. And in the 1950s and 1960s, he pioneered
photoelectric photometry with a novel four-colour system, now called
Strömgren photometric system. Apart from the Danish observatory of Brorfelde, Strömgren was active in the early organisation of the joint European observatory of
ESO
The European Southern Observatory is an astronomical research organisation.
ESO may also refer to:
*Employee stock option (also: executive stock option)
*'' Ether Saga Odyssey'', a fantasy massively multiplayer online role-playing game
*''The Elde ...
at
La Silla in
Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
.
Honors
Awards
*
Bruce Medal
The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was ...
(1959)
*
Gold Medal of the Royal Astronomical Society
The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...
(1962)
*
Henry Norris Russell Lectureship The Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research. The idea for the lectureship came from then society President Harlow Shapley in 1945, ...
(1965)
*
Janssen Medal from the
French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
(1967)
Memberships
* Member of the
American Academy of Arts and Sciences
The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...
(1955)
* Member of the United States
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...
(1971)
* Member of the
American Philosophical Society
The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...
(1973)
Named after him
*
Asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
1846 Bengt
*
Strömgren age
*
Strömgren photometry
*
Strömgren spheres
*
Strömgren integral
In mathematics and astrophysics, the Strömgren integral, introduced by while computing the Rosseland mean opacity, is the integral
In mathematics, an integral is the continuous analog of a Summation, sum, which is used to calculate area, ...
Miscellaneous
*Asteroid
1493 Sigrid, named after his wife
References
Sources
* Svend Cedergreen Bech (ed.):
Dansk Biografisk Leksikon' (1979–84), 3rd ed. Put on-line by Den Store Danske in 2011.
Bengt Strömgrens life among the stars Niels Bohr Institute
Bruce Medalist Bengt Strömgren* Autobiography in a celebrative commemorative published by University of Copenhagen November 1930 (176-78) (''Berlingske Tidende'' id. 17.9.1962).
* Knude, Jens, ''Bengt Stromgren's Work in Photometry'', in A.G.D. Philip, A.R. Upgren and K.A. Janes, eds., "Precision Photometry: Astrophysics of the Galaxy", Proceedings of the conference held 3–4 October 1990 at Union College, Schenectady, NY (Davis Press, Schenectady, NY, 1991).
* Rebsdorf, Simon Olling (May 2003): ''Bengt Strömgren: growing up with astronomy, 1908 - 1932'', Journal for the History of Astronomy (ISSN 0021-8286), Vol. 34, Part 2, No. 115, pp. 171 – 199 (2003)
* Rebsdorf, Simon Olling (August 2004): ''The Father, the Son, and the Stars: Bengt Strömgren and the History of Twentieth Century Astronomy in Denmark and in the USA''. Ph.D. dissertation, University of Aarhus.
* Rebsdorf, Simon Olling (February 2007):
Bengt Strömgren: Interstellar Glow, Helium Content, and Solar Life Supply, 1932–1940'. Centaurus, Vol. 49, Issue 1, pages 56–79.
* Gustafsson, Bengt (2009):
Bengt Strömgren’s Approach to the Galaxy', in J. Andersen, J. Bland-Hawthorn & B. Nordström, eds., "The Galaxy Disk in Cosmological Context." Proceedings IAU Symposium No. 254 (Cambridge Univ. Press, 2009), pp. 3–16.
External links
Bruce Medalist Bengt Strömgren
{{DEFAULTSORT:Stromgren, Bengt
1908 births
1987 deaths
20th-century Danish astronomers
University of Copenhagen alumni
Academic staff of the University of Copenhagen
Danish people of Swedish descent
University of Chicago faculty
Institute for Advanced Study faculty
Science teachers
Recipients of the Gold Medal of the Royal Astronomical Society
Foreign associates of the National Academy of Sciences
Scientists from Gothenburg
Presidents of the International Astronomical Union
International members of the American Philosophical Society