Hubble Space Telescope Imaging of the North Polar Aurora on Jupiter

The first direct images of the Jovian aurora at ultraviolet wavelengths were obtained by the Hubble Space Telescope Faint Object Camera near the time of the Ulysses spacecraft encounter with Jupiter on 8 February 1992. The auroral oval is not uniformly luminous. It exhibits a brightness minimum in the vicinity of longitude 180 degrees . In the few images available, the brightest part of the oval occurs in late afternoon Jovian time. The observed oval is not concentric with calculated ovals in the O(6) model of Connerney. The size of the oval is consistent with auroral particles on field lines with magnetic L parameter >8, indicating significant migration from lo, its torus, or both, if these are their origins.