Daniel Chalonge

Daniel Chalonge was a French astronomer and astrophysicist. He was born in Grenoble and studied in Paris under Charles Fabry. Chalonge worked as an astronomer at the Observatoire de Paris, the Observatoire d'Haute Provence and the Swiss Jungfraujoch Scientific Station. One of the founders of the Institut d'astrophysique de Paris, his studies included the stellar spectrum of hydrogen, stellar photometry and classification, and measurement of the ozone layer. During the Nazi occupation of France, Chalogne assumed the position of director of the Institut d'astrophysique de Paris after the previous director, Henri Mineur, was arrested by the Gestapo. Chalonge developed a microphotometer, which was subsequently named after him. Between 1936 and 1982 he authored over 90 scientific papers.