Detection of Auroral Emissions from Callisto’s Magnetic Footprint at Jupiter

HST observations of Jupiter’s aurora in a large
campaign reveal several cases where the main oval
emission appeared at unusually low latitudes, making
it possible to search for the first time for auroral
emissions from the magnetic footprint of Callisto
without the overlapping bright emissions from the
main oval. Several cases have been found where
point-source emissions have now been detected from
locations consistent with Callisto’s magnetic
footprint on Jupiter at a brightness of ten’s of kilo-
Rayleighs. These observations confirm that there is
an electrodynamic interaction between Callisto and
Jupiter’s magnetospheric environment that is similar
to those at Io, Europa, and Ganymede, which all have
auroral footprints. The properties of the emissions
and a comparison with other observations and
theoretical expectations will be presented in this
paper.