Ions of Jovian origin observed by Voyager 1 and 2 in interplanetary space

Burst‐like and long‐lived ion fluxes (E ≳ 30 keV) of Jovian origin have been observed in interplanetary space by the LECP instrument on the Voyager 1 and 2 spacecraft. Burst (few minute duration) events are observed at distances greater than 0.6 AU (1200 R J ) from Jupiter. These events are highly anisotropic and possess steep energy spectra, while long‐lived (>8 hour duration) events have relatively steady fluxes at low energies, strong anisotropies that decay with time, and a variable high energy component. Both types of events usually display simultaneous onsets and sharp cutoffs for all energies, an excess of atomic number Z ≥ 6 particles compared to solar and interplanetary events, and particle flow directions pointed away from Jupiter along the local interplanetary magnetic field. The origin for the long‐lived events appears to be inside the bow shock of the planet.