HR: 0800h
AN: P11A-0092    [Abstracts]
TI: The Variation of Io's Auroral Footprint Brightness with the Location of Io in the Plasma Torus
AU: * Serio, A
EM: drew@sciences.sdsu.edu
AF: San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 United States
AU: Clarke, J T
EM: jclarke@bu.edu
AF: Boston University, 725 Commonwealth Ave, Boston, MA 02215 United States
AB: Observations of Jupiter`s aurora with HST/STIS since 1997 have shown bright and variable UV auroral emissions from the magnetic footprint of Io. The STIS images have sufficient angular resolution and sensitivity to perform a high quality comparison of the brightness of these emissions with various parameters related to Io, such as the location of Io in the plasma torus, its latitude, its local time, etc. Such correlations can be used to determine the nature of the complex electromagnetic interaction of Io with Jupiter's magnetic field and the plasma torus. Several corrections must be applied to the images for a self-consistent study, including mapping and projection of the location on the planet for a consistent view and a correction for limb brightening of the optically thin emissions as seen from the earth. These have been carefully tested and applied, after which one and only one correlation has been found. The footprint auroral emissions appear brightest when Io is centered in the plasma torus, indicating both that the interaction is strongest and that the current and/or particle acceleration communicated to the planet is greatest in this orientation. The results of this study will be presented along with discussion of the different theoretical models for the Io interaction.
DE: 5706 Aurorae
DE: 5719 Interactions with particles and fields
DE: 6218 Jovian satellites
SC: Planetary Sciences [P]
MN: Fall Meeting 2005