Time-Resolved Observations of Jupiter's Far-Ultraviolet Aurora
Casertano, Stefano; Ballester, Gilda E.; Krist, John E.; Crisp, David; Holtzman, Jon A.; Trauger, John T.; Gallagher, John S., III; Hester, J. Jeff; Westphal, James A.; Mould, Jeremy R.; Hoessel, John G.; Clarke, John T.; Harris, Walter M.; Evans, Robin W.; Stapelfeldt, Karl R.; Burrows, Christopher J.; Griffiths, Richard E.; Scowen, Paul A.; Watson, Alan M.; Meadows, Vikki; Sahai, Raghvendra; Burgh, Eric B.
Abstract
Simultaneous imaging and spectroscopic observations of Jupiter's far-ultraviolet aurora covering half a jovian rotation were made on 31 May 1994. The Hubble Space Telescope Wide Field Planetary Camera 2 images revealed dramatic and rapidly changing auroral features, including discrete longitudinal structures along the auroral ovals, with variable contrast; a poleward offset in a north oval sector, showing equatorward motion near dusk; emissions polewards of the ovals, apparently co-rotating; and a bright event developing near the dawn limb. Viewing geometry effects explain the rotational intensity modulation observed by the International Ultraviolet Explorer, without intrinsic longitudinal asymmetries.