! File: 3644C.PROP ! Database: PEPDB ! Date: 19-FEB-1994:14:53:44 coverpage: title_1: A SEARCH FOR THE HYDROXYL RADICAL IN SATURN'S MAGNETOSPHERE sci_cat: SOLAR SYSTEM sci_subcat: GIANT PLANETS proposal_for: GO pi_fname: DONALD pi_mi: E. pi_lname: SHEMANSKY pi_inst: UNIV. OF SOUTHERN CALIFORNIA pi_country: USA pi_phone: 213-740-7184 hours_pri: 5.00 num_pri: 1 fos: Y funds_amount: 52691 funds_length: 12 off_fname: CORNELIUS off_mi: J. off_lname: PINGS off_title: PRVST/VP ACAD AFF. off_inst: UNIVERSITY OF SOUTHERN CALIFORNIA off_addr_1: DEPT. OF CONTRACTS AND GRANTS off_addr_2: UNIVERSITY OF SOUTHERN CALIFORNIA off_city: LOS ANGELES off_state: CA off_zip: 90089 off_country: USA off_phone: 213-740-7762 ! end of coverpage abstract: line_1: We propose to observe the Saturn magnetosphere to investigate line_2: the abundance and distribution of the hydroxyl radical (OH). line_3: This species is diagnostic of basic properties of the line_4: magnetosphere and erosion rates of the icy satellites and rings. line_5: The presence of significant numbers of heavy neutrals in the line_6: magnetosphere have been inferred from energy loss rates line_7: required to explain the observed population of line_8: cold electrons. If this interpretation is correct large line_9: source rates are required. We have constructed a physical line_10: chemistry model for the Saturn magnetosphere that predicts line_11: neutral and plasma species partitioning. The parametric line_12: requirements to match observed plasma conditions with this line_13: model results in the prediction of large amounts of neutral line_14: oxygen and moderate amounts of OH, with sensitivity to ion line_15: diffusive loss rates. The abundance of OH inside 8 Saturn line_16: radii is predicted to be observable with HST through its line_17: fluorescent emission centered near 3085A. Direct estimates of line_18: OH densities, coupled with the chemical kinetic model, will line_19: provide a definitive constraint on icy satellite erosion line_20: rates. ! ! end of abstract general_form_proposers: lname: SHEMANSKY fname: DONALD title: PI mi: E. inst: UNIV. OF SOUTHERN CALIFORNIA country: USA ! lname: MATHESON fname: PHILIP mi: L. inst: UNIV. OF SOUTHERN CALIFORNIA country: USA ! lname: HALL fname: DOYLE mi: T. inst: UNIV. OF SOUTHERN CALIFORNIA country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: A total of 5 hours of exposure on the Saturn line_2: magnetosphere will be made approximately line_3: 37 arcseconds from planet center on the dusk line_4: (western) ansa of the Saturn satellite orbits. line_5: Exposure times will be confined to the darkside to line_6: minimize scattered Earth shine. line_7: Exposures must be made with no satellites in the field line_8: of view, a minimum of 6 arcsec from the line of sight. line_9: The Faint Object Spectrograph (FOS) Red Digicon will line_10: be used with the G270H grating and line_11: the 2.0-Bar aperture. The Red Digicon using the G270H line_12: yields the greatest detection line_13: efficiency at the OH 308.5 nm band. The 2.0-Bar line_14: aperture is the largest available and is selected line_15: here because a maximal field of view is necessary to line_16: enhance the signal-to-noise ratio (SNR). line_17: To achieve an SNR of approximately 10 for the expected line_18: approximately 20 R 308.5 nm band, an exposure duration line_19: of 5 hours is necessary because of competitive line_20: zodiacal and diffuse galactic sky line_21: background signals. ! question: 4 section: 1 line_1: An extraterrestrial OH A - X (0,0) feature cannot be line_2: detected with ground based apparatus line_3: because of strong airglow foreground signals and line_4: atmospheric absorption. The IUE line_5: spacecraft has detected the feature in comets, but the line_6: intensity expected for the Saturn line_7: magnetosphere effectively lies below its detection line_8: threshold. A 20 R Saturn magnetosphere line_9: emission would require a prohibitively long IUE line_10: exposure time (greater than 60 hours) to detect line_11: with an acceptable signal-to-noise ratio (SNR). The line_12: HST is the only currently operating line_13: platform from which these observations may be performed. ! question: 5 section: 1 line_1: There is a possible need for real time data to line_2: evaluate the magnitude of off-axis scattering. line_3: The exposure schedule must be windowed to exclude line_4: satellites from the field. ! question: 6 section: 1 line_1: Dark time exposures are requested to minimize line_2: contamination of weak signal. line_3: OH has never been observed in the Saturn line_4: magnetosphere and estimated abundance is uncertain. ! question: 7 section: 1 line_1: The FOS spectra will be reduced using the standard line_2: procedures contained in the Image line_3: Reduction and Analysis Facility (IRAF) Space Telescope line_4: Science Data Analysis Software line_5: (STSDAS) package. This software is currently line_6: available at the University of Southern California. ! question: 8 section: 1 line_1: ! question: 9 section: 1 line_1: No data. ! question: 10 section: 1 line_1: A SUN SparcStation computer with the IRAF/STSDAS line_2: software is available at the line_3: University of Southern California, Department of line_4: Aerospace Engineering for use in this research program. line_5: The CPU time to reduce and analyze these data are line_6: anticipated to have a moderate impact line_7: on the current computing load. ! !end of general form text general_form_address: lname: SHEMANSKY fname: DONALD mi: E. category: PI inst: UNIV. OF SOUTHERN CALIFORNIA addr_1: DEPT AEROSPACE ENGINEERING addr_2: 854 W. 36TH PLACE addr_3: UNIV. OF SOUTHERN CALIFORNIA city: LOS ANGELES state: CA zip: 90089 country: USA phone: 213-740-7184 telex: 4720490 USC LSA ! ! end of general_form_address records ! No fixed target records found solar_system_targets: targnum: 1 name_1: SATMAG-DUSK descr_1: OFFSET SATURN lev1_1: STD = SATURN, ACQ=1.5 lev2_1: TYPE=TORUS, lev2_2: LONG=90,LAT=0, lev2_3: RAD=228000, lev2_4: POLE_LAT=90,POLE_LONG=0 wind_1: WND1 = 01-JUL-92 TO 01-SEP-92 comment_1: ESTIMATED BAND BRIGHTNESS 20 R comment_2: CONTINUUM IS SKY BACKGROUND comment_3: SEP OF LOS ENCELADUS FROM EARTH GT comment_4: SEP OF LOS TETHYS FROM EARTH GT 10 comment_5: SEP OF LOS DIONE FROM EARTH GT 10 comment_6: SEP OF LOS RHEA FROM EARTH GT 12 comment_7: SEP OF LOS TITAN FROM EARTH GT 14 comment_8: SEP OF LOS HYPERION FROM EARTH GT 5 comment_9: SEP OF LOS IAPETUS FROM EARTH GT 7 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 1.000 targname: SATMAG-DUSK config: FOS/RD opmode: ACCUM aperture: 0.7X2.0-BAR sp_element: G270H wavelength: 2225-3281 num_exp: 15 time_per_exp: 800S s_to_n: 5 req_1: DARK TIME; req_2: CYCLE 2 comment_1: ESTIMATED MAX FLUX 5 E-17 comment_2: ERG CM-2 S-1 A-1 ARCSEC-2 comment_3: AT RESOLUTION OF 0.7X2-BAR APERTURE. ! ! end of exposure logsheet ! No scan data records found