Astrophysicist, he discovered the first interstellar molecule and was President of the International Astronomical Union.

Polidore Swing Bio


olidore Swings, known as Pol, was born in Ransart near Charleroi on 24 September 1906. His parents were of modest means and probably did not envisage higher education for their newborn son. But young Pol proved to be a brilliant student throughout his primary education. His teachers noticed him and one of them in particular convinced his parents to let him continue his studies at the Charleroi Athenaeum. Pol Swings will say that it is to the foresight of his teachers and the sacrifice of his parents that he owes his career.

Sacrifices are indeed necessary when one starts secondary studies in 1917, the darkest and hardest year of the German occupation. Young Pol made his share of sacrifices, exhausting himself on long walks in the morning and evening to attend his classes. This did not prevent him from succeeding brilliantly, to the point of receiving a special government award in 1923 at the end of his humanities!

Desiring to become an astrophysicist after reading the book by the astronomer Camille Flammarion, "Astronomie Populaire", Pol Swings began his doctorate in physical sciences and mathematics at the University of Liège. He completed his studies with a thesis in celestial mechanics under the direction of Marcel Dehalu, then director of the Cointe observatory.

Swings School

After a year in Paris (1927-1928) during which he attended courses at the Sorbonne, the Collège de France, the Optics Institute and especially the Meudon Observatory, he returned to Liège, became Dehalu's assistant and set up a small spectroscopy laboratory at the Cointe Observatory, the embryo of an Astrophysics Institute which continued to develop in the years that followed. At the same time, he continued to train in spectroscopy, particularly in Poland, at the Institute of Physics in Warsaw. In 1931, Pol Swings received a state doctorate and crossed the Atlantic for the first time to the Yerkes Observatory at the University of Chicago. There he discovered a country and a way of life and work that he would always remain close to - he referred to this country as "the home of astrophysics" - and he met Otto Struve, a brilliant astronomer of Russian origin, with whom he became a friend and with whom he would collaborate for decades.

Back in Liège in 1932, he was appointed lecturer and developed "his" Astrophysics Institute which, under his impetus, was to acquire an international reputation.

The young researcher was beginning to be recognised, his publications were multiplying and, moreover, he was proving to be an enthusiastic teacher and a tireless facilitator. He launched the tradition of Friday seminars at the Institut d'Astrophysique, during which researchers and students would meet. But above all, the young professor (he was appointed in 1935) did what he would continue to do until his death: identify the best elements among his students and establish 'career plans' for them, constantly recommending them to one or other of his many international contacts. A "Swings School" was established.

In 1939, Pol Swings returned to the USA - fortunately in the company of his wife - and to the University of Chicago. It was a bad time, of course: events forced him to stay in the United States for several years. Until 1943, he taught in Chicago while working relentlessly with Otto Struve (they co-authored 34 publications between 1940 and 1943!), mainly on the spectra of so-called hot stars, many of whose lines they identified. Pol Swings then moved to California and took part in the war effort at the Ray Control Company in Pasadena where he used his knowledge of optics to improve periscopes for submarines.

P.Swings Roi Bauduoin

Polidore Swings (right) with Queen Fabiola and King Baudouin at the Observatory of Haute-Provence.
Amateur astronomer, the King liked to observe the stars. j.P. Swings

Organising space research

The post-war period in Belgium was synonymous with reconstruction. Without neglecting his personal research - he was awarded the Prix Francqui in 1948 - Pol Swings set about relaunching the activities of the Institute of Astrophysics and, in 1949, he created the Colloques internationaux d'Astrophysique de Liège, which immediately established itself in the landscape of international scientific meetings: more than ten Nobel Prize winners took up residence there! While continuing his spectroscopic research on comets and many other celestial objects (see article above), Pol Swings pursued a parallel career as a tireless organiser of research programmes in the space field.

Even before the war, Swings had been called upon to serve as Secretary General of Commission 29 of the International Astronomical Union (IAU), the commission devoted to the study of stellar spectra. He became chairman after the war and was soon a member of various other commissions. His reputation as a scientist and his work within the Union led to his appointment as Vice-President in 1952, a position he held until 1958. In 1964, he was elected President of the Union for the following three-year period (1967-1970). This is probably the greatest proof of the esteem in which astronomers hold one of their own!

He also ensured that the Haute-Provence Observatory, then the largest observatory in Europe, became a bit of a Liège institution. Pol Swings initiated a collaboration that enabled generations of students and researchers from Liège to become familiar with the use of telescopes and the observation of stars. One of the reasons for this was that he obtained the financing of a 'Belgian' telescope housed in a dome of the observatory.

But what is probably less well known is what Belgium owes to Pol Swings in the field of space research. He was constantly involved in bringing together Belgian teams in international organisations. Thanks to him, Belgium was a founding member of a whole series of organisations such as COSPAR (Committee on Space Research) as early as 1958, ESO (European Southern Observatory) in 1962 and ESRO (European Space Research Organisation) in 1964, which gave rise to the ESA (European Space Agency) in 1975. In 1962, he and H.E. Butler of the Edinburgh Observatory proposed building a satellite carrying a telescope to observe the sky in the ultraviolet. He then entrusted his assistant at the time, André Monfils, with the task of setting up a 'Space' working group within the Institute of Astrophysics, which would become, under the latter's leadership, first the IAL Space and then the CSL (Centre Spatial de Liège).

A member of numerous associations and institutions, including the Royal Academy of Belgium, and the recipient of numerous awards, Pol Swings died on 28 October 1983, leaving the University of Liège with an Institute of Astrophysics that continues to occupy an enviable place among research centres of this type in the world.

Learn more

his research

his scientific publications


  • Robert Halleux, Geert Vanpaemel, Jan Vandersmissen en Andrée Despy-Meyer (eds.), Histoire des sciences en Belgique, 1815-2000, Brussels: Dexia/La Renaissance du livre, 2001.
  • Notice sur Pol Swings, by P. Ledoux, Académie royale de Belgique, Annuaire 1988.
  • Swings, by Léo Houziaux, Nouvelle biographie nationale, volume 7, pp 331-336, 2003.
  • Swings, Curriculum vitae; List and analysis of publications, n.d. Institute of Astrophysics.
  • Pol Swings, by Guy Ronflette, in Chroniques ransartoises, issue 7, n.d., Cercle d'étude pour l'histoire de Ransart.
updated on 1/13/23

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