HR: 0830h
AN: P21B-01    [Abstracts]
TI: Saturn's Auroras from the Cassini Ultraviolet Imaging Spectrograph
AU: * Pryor, W R
EM: wayne_pryor@centralaz.edu
AF: Central Arizona College, 8470 N. Overfield Road, Coolidge, AZ 85228 United States
AU: West, R A
EM: robert.a.west@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Stewart, I A
EM: ian.stewart@lasp.colorado.edu
AF: LASP/University of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: Shemansky, D E
EM: dons@hippolyta.usc.edu
AF: Univ. Southern California/Dept. of Aerospace Engineering, 854 West 36th Pl., Los Angeles, CA 90089 United States
AU: Ajello, J M
EM: jajello@mail1.jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Esposito, L W
EM: larry.esposito@lasp.colorado.edu
AF: LASP/University of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: Colwell, J E
EM: josh.colwell@lasp.colorado.edu
AF: LASP/University of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: McClintock, W E
EM: william.mcclintock@lasp.colorado.edu
AF: LASP/University of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: Jouchoux, A
EM: alain.jouchoux@lasp.colorado.edu
AF: LASP/University of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: Hansen, C J
EM: cj@frostrus.jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Crary, F J
EM: fcrary@swri.edu
AF: Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78228 United States
AU: Kurth, W S
EM: william-kurth@uiowa.edu
AF: University of Iowa, 203 Van Allen Hall, Iowa-City, IA 52242 United States
AU: Clarke, J T
EM: jclarke@bu.edu
AF: Boston University Center for Space Physics, 725 Commonwealth Ave., Boston, MA 02215 United States
AU: Baines, K A
EM: kbaines@mail1.jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: Cassini's Ultraviolet Imaging Spectrograph (UVIS) has begun making detailed studies of Saturn's auroras. Two long slit spectral channels are used to obtain EUV data from 56.3-118.2 nm and FUV data from 111.5-191.3 nm. 64 spatial pixels along each slit are combined with slit motion to build up spectral images of Saturn, with sufficient spatial resolution to reveal Saturn's auroral oval. Observed emissions include H Lyman-alpha and H2 bands from Saturn's auroras and dayglow. The auroral spectrum is remarkably similar to that of Jupiter, showing short-wavelength FUV absorption due to methane, CH4. Saturn's auroral and dayglow spectra show significant differences. Saturn's aurora is observed to vary in brightness by at least a factor of four. The brightest auroral emissions seen so far occurred after 2004 day 207 19:30 when Cassini CAPS recorded passage of a solar wind shock. The enhanced auroral brightness persisted for days, and is seen at both poles of Saturn. Cassini RPWS observed enhanced auroral kilometric emissions during several auroral brightening events seen by UVIS. A campaign of Hubble Space Telescope UV imaging with ACS (Advanced Camera for Surveys) of Saturn's dayside southern auroral zone is planned for 2005 February 17. Cassini UVIS and VIMS will be observing Saturn's nightside northern aurora during this period. The UVIS long slit will be aligned with lines of latitude on Saturn, providing information about intensity and spectral variations along the auroral oval.
DE: 0310 Airglow and aurora
DE: 0343 Planetary atmospheres (5405, 5407, 5409, 5704, 5705, 5707)
DE: 6275 Saturn
SC: Planetary Sciences [P]
MN: 2005 Joint Assembly