HIGHLIGHTING THE HISTORY OF FRENCH RADIO ASTRONOMY. 4: EARLY SOLAR RESEARCH AT THE ECOLE NORMALE SUPERIEURE, MARCOUSSIS AND NANCAY

The first tentative steps in solar radio astronomy took place during the 1940s and early 1950s as physicists and engineers in a number of countries used recycled World War II equipment to investigate the flux levels and polarisation of solar bursts and emission from the quiet Sun, and sought to understand the connection between this emission and optical features in the solar photosphere and chromosphere. There was also an abiding interest in the terrestrial effects of this solar radio emission. Among these solar pioneers were French radio astronomers from the Ecole Normaleuperieure in Paris. In this paper we review the early solar observations made by them from Paris, Marcoussis and Nancay prior to the construction of a number of innovative multi-element solar interferometers at the Nancay field station in the mid-1950s.