title: Plasma observations near uranus: initial results from voyager 2.
abstract: Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of L = 5, whereas the hot component is excluded from the region inside of that L shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at L = 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth.
authors.forename: H S
authors.initials: HS
authors.lastname: Bridge
authors.forename: J W
authors.initials: JW
authors.lastname: Belcher
authors.forename: B
authors.initials: B
authors.lastname: Coppi
authors.forename: A J
authors.initials: AJ
authors.lastname: Lazarus
authors.forename: R L
authors.initials: RL
authors.lastname: McNutt
authors.forename: S
authors.initials: S
authors.lastname: Olbert
authors.forename: J D
authors.initials: JD
authors.lastname: Richardson
authors.forename: M R
authors.initials: MR
authors.lastname: Sands
authors.forename: R S
authors.initials: RS
authors.lastname: Selesnick
authors.forename: J D
authors.initials: JD
authors.lastname: Sullivan
authors.forename: R E
authors.initials: RE
authors.lastname: Hartle
authors.forename: K W
authors.initials: KW
authors.lastname: Ogilvie
authors.forename: E C
authors.initials: EC
authors.lastname: Sittler
authors.forename: F
authors.initials: F
authors.lastname: Bagenal
authors.forename: R S
authors.initials: RS
authors.lastname: Wolff
authors.forename: V M
authors.initials: VM
authors.lastname: Vasyliunas
authors.forename: G L
authors.initials: GL
authors.lastname: Siscoe
authors.forename: C K
authors.initials: CK
authors.lastname: Goertz
authors.forename: A
authors.initials: A
authors.lastname: Eviatar