Soon after the creation in 1953 of the Nançay radio-astronomical observatory, the construction of a large radio-telescope, able to register the radio signals of distant galaxies, was envisaged.  This project, which French industry could only just manage, was in part realized with very limited resources, so that it was only finished in 1967. The large radio-telescope is still in operation, following many upgrades. It is now to a large extent used for the timing of pulsars, the very dense stars that rotate very fast and beam radio waves in specific directions, like beacons.

caption : The large radio telescope under construction - credits : Observatoire de Paris

To know more : The large Nançay radiotelescope