Plasma Wave Observations at Uranus from Voyager 2.
Progress rept. for period ending Feb 86,
IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY
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Radio emissions from Uranus were detected by the Voyager 2 plasma wave instrument about 5 days before closets approach at frequencies of 31.1 and 56.2 khz. The bow shock was identified by an abrupt broadband burst of electrostatic turbulence about 10 hours before closest approach at a radial distance of 23.5 ru. Once inside of the magnetosphere strong whistler mode hiss and chorus emissions were observed at radial distances less than about 8 R sub u, in the same region where the energetic particle instruments detected intense fluxes of energetic electrons. A variety of other plasma waves, such as f sub c electron cyclotron waves, were also observed int his same region. At the ring plane crossing the plasma wave instrument detected a large number of impulsive events that are interpreted as impacts of micron sized dust particles on the spacecraft. The maximum impact rate was about 20 to 30 impactssec, and the north-south thickness of the impact region was about 4,000 km. In this paper presents an overview of the principal results from the plasma wave instrument, starting with the first detection of radio emissions from Uranus, and ending a few days after closest approach.