[en] NEPTUNE (PLANET) ; PLANETARY RINGS ; TELESCOPES ; DATA ACQUISITION ; EPHEMERIS TIME
[en] The unexpected rediscovery of the Uranian rings in 1977 and the discovery of the faint Jovian rings in 1979 led to an intensified search for rings around Neptune. A description is given of observing programs at the European Southern Observatory (ESO) in Chile, which led to a discovery of such a ring, taking into account the utilization of the ESO 0.5 m and 1 m telescopes. The discovery is based on observations made on the night of July 22, 1984, in connection with a stellar occultation by the planet. Explanations for the observed differences in shape and timing of the occultation event, as recorded by both telescopes, are discussed. The obtained conclusions could be confirmed by a study of the results of a group of American astronomers working at the Cerro Tololo observatory. The observations strongly favor the existence of, at least, a part of a ring which has a width of roughly 10-15 km over a length of at least 100 km.