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    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID 5341
                                                       Report Date: 18-Jul-95:17:12
                                                       Version: **********
                                                       Check-in Date: **********

1.Proposal Title:
HIGH RESOLUTION IMAGING OF SATURN'S UV AURORA: CYCLE4MEDIUM
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2. Scientific Category   3. Proposal For  4. Proposal Type        5. Continuation ID
SOLAR SYSTEM                GO                                       <none>
Sub Category
GIANT PLANETS
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6. Principal Investigator   Institution                    Country    Telephone
 Jean-claude Mc Gerard      UNIVERSITE DE LIEGE            BELGIUM    32-41-529980

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7. Abstract
Previous HST observations made with the FOC have demonstrated the ability of the HST
to provide high spatial resolution images of the ultraviolet jovian aurora.  We
propose to take advantage of the restored post-COSTAR spatial resolution of the FOC
to obtain high resolution images of the north UV SATURN aurora. Saturn's UV aurora
will be imaged for the first time.  A complete rotation of the north polar region
will be observed with the FOC nearly 12 years after the Voyager flyby.  These
discovery measurements are expected to provide a wealth of new information
concerning the intensity, morphology, time variation and relation with the polar
haze present at high latitudes.
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9. Est obs time (hours) pri: 3.00     par: 0       10. Num targs pri: 1      par: 0
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11. Instruments requested:  FOC
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I. GENERAL FORM    Proposal 5341
PI:  Jean-claude Mc Gerard
Proposal Title:
HIGH RESOLUTION IMAGING OF SATURN'S UV AURORA: CYCLE4MEDIUM
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1. Proposers:
Proposers                        Institution                       Country       ESA
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 Jean-Claude Mc Gerard           4330                              BELGIUM        X
 Vincent J. Dols                 4330                              BELGIUM        X
 Renee Prange                    5448                              FRANCE         X
 Francesco Paresce               3470                              USA            X
 Hunter J. Waite                 3440                              USA
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  3. Description of proposed observations.
  We plan to explore with the improved spatial resolution (and the subsequent
 increased sensitivity to near point objects) the morphology of the Saturnian
 aurora by imaging the north polar region of the planet. Based on the accumulated
 experience of the team in the use of the FOC to image the UV aurora with the FOC,
 we know that these objectives will be best achieved by using the camera in the
 following configuration: - F/96 optical relay in the 512zx1024 zoomed pixel
 format (14x14 arcsec) -8-bit words -F152M+F175W filters This filter combination
 was successfully used in GTO program 1269. Previous onservations have shown that
 the count rate is well below saturation of the 8-bit words. The SATURNIAN AURORA
 program is exploratory. it will consist in a series of 8 images taken on
 consecutive HST orbits over more than a Saturn rotation. It will start at a phase
 when the CML longitude is in the sector where the Voyager UVS detected the most
 intense auroral emission. The program will be implemented as follows: 1- A near
 UV image of Saturn's north polar region to define the location of the planetary
 limb 2- One 20-min exposure of the north aurora at 153 nm for initial CML
 longitude 50 <Lambda< 180 deg. 3- Exposure (2) is repeated during the following 7
 consecutive HST orbits in   order to cover a full Saturn rotation and overlap
 with the initial longitude sector to search for possible time variations.
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  4. Justification of need for HST observations.
  The IMAGING CAPABILITY of the FOC/HST in the ultraviolet is unique and essential
 to reach our scientific objectives.  No other spacecraft or ground equipment can
 provide images of the UV Saturnian aurora. So far,  Voyager UVS, IUE and HST
 observations have provided important information on the morphology of the UV
 jovian aurora, thereby opening a new era of scientific study of Jupiter 's
 magnetospheric environment and physical processes.  Previous FOC/HST observations
 have demonstrated the ability of HST to monitor the spatial distribution of
 auroral phenomena from Earth orbit. In the case of Saturn's aurora, the
 information provided by UVS was extremely limited due to the relative sizes of
 the spectrometer slit and the auroral oval. The Voyager UVS measurements have
 clearly established the existence of a region of auroral emission surrounding the
 poles whose global exists concerning the exact location of the emission, its
 latitudinal and longitudinal extent, the intrinsic brightness of the aurora and
 its exact relation with the radio kilometric emission.  It has therefore been
 very difficult until now to build models of the specific origin of the
 precipitating particles and to derive energy fluxes into the planets' upper
 atmospheres. This program provides a unique opportunity to accomplish a major
 step towards the understanding of the saturnian magnetospheric physics using an
 approach whose feasibility was now been clearly demonstrated with previous HST
 observations of the Jovian aurora.
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  5. Description of special scheduling requirements.
  This program is not time-critical.  However, the observations will be best at or
 near Saturn's opposition when the angle subtended by the auroral ovals is
 maximum.  This is NOT however a condition.
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  6. Description of special calibration exposures.
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  8. Additional comments or special requests.
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  9. Description of previous HST work.
  1.  GTO program 1269 (F.  Paresce, PI) 2.  GO cycle 3 program 4608,(J.C. Gerard,
 PI) 3.  Discretionary time (ID 4005),(Stern, PI;  Waite, Co-I) 4.  GTO/FOC 1253,
 (F.Paresce, PI) 5.  GO 3511, ( J.Clarke, PI;  R.  Prange, Co-I) PUBLICATIONS:
 First Results from the FOC:  Imaging the Core of R Aqr, F.  Paresce et al.,Ap. J.
 Lett., 369, L67, 1991 Blue Stragglers in the Core of the Globular Cluster 47 Tuc,
 F.Paresce et al., Nature, 232, 297, 1991 Io surface ultraviolet imaging with the
 HST Near UV imaging of Jupiter's satellite Io with HST, Astron.  Astrophys, 1992.
 Far ultraviolet imaging of the jovian aurora with the Hubble Space Telescope V.
 Dols et al, Geophys.  Res. Lett., 19, 1803,  1992. High resolution near UV
 observation of Jupiter's satellite Io with the HST, F. Paresce et al, Proceedings
 of the HST Workshop, Sardinia, 493, 1992. Far ultraviolet imaging of Jupiter's
 northern polar regions with the FOC J.C. Gerard et al, Proceedings of the HST
 Workshop, Sardinia, 505, 1992. The Structure of the Inner Arcsecond of R Aqr
 observed with HST, D.Burgarella and F. Paresce, Ap.  J.  Lett., 389, L29, 1992
 Solar system observations with HST, F.  Paresce and J.C.  Gerard, in Proceedings
 of the International Space Year Conference Munich, 1992, in press.   High
 resolution near UV observation of Jupiter's satellite Io with the Hubble Space
 Telescope, V.  Dols et al, paper presented at the EGS General Assembly,
 Edinburgh, Ann.  Geophys.  Suppl., 10, C498, 1992. First Ly-alpha images of the
 jovian aurora with the HST, J.C.  Gerard et al., abstract, presented at the EGS
 General Assembly, Edingburgh, April 1992. Multispectral Observations of Jovian
 Aurora, H.  Waite et al., abstract, paper presented at the UCLA conference, June
 22-26 and at the Variable Phenomena in Jovian Planetary Systems, Annapolis July
 13-16, 1992. Analysis of the first image of the the jovian aurora at Lyman alpha
 obtained with the HST, R.  Prange et al, paper presented at the conference
 "Variable phenomena in jovian planetary systems", Annapolis, July 13-16, 1992.
 Observations of the H and H2 ultraviolet aurora with the HST Faint Object Camera
 , J.C.  Gerard et al, abstract, DPS meeting,Munich, 1992. High resolution
 observations of the morphology of the Jovian far UV aurora with the HST, V.Dols
 et al,EGS General Assembly, Ann. Geophys. Suppl., 11, C492, 1993 Field aligned
 currents and auroral emission in the Jovian magnetosphere, M.K Dougherty et al.,
 idem, C493, 1993. Far UV imaging of Saturn and its rings with the HST,J.C. Gerard
 et al, idem, C461, 1993.
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 10. Resources to be supplied by investigator's institution(s).
  - workstations are available in several institutions for data reduction, fitting
 and comparison with models -university computer time is available in all
 institutions for numerical modeling and comparison with data -1 full time
 research assistant in atmospheric physics (PRODEX ESA program) funded by the
 Belgian Government for HST data analysis -1 graduate student in plasma physics
 (France) and one graduate student in astrophysics (Liege). - Funds are available
 for this project through various scientific agencies: SPPS(B), CNRS(F), NASA and
 ESA.  Financial support is requested by the US Co-I.
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11. Address Information
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Name:  JEAN-CLAUDE MC GERARD                               Category: PI
Institution: 4330
Address:  AVENUE DE COINTE, NB 5
City: LIEGE                                     State:
Zip Code: 4000                                  Country: BELGIUM
Telephone: 32-41-529980
Telex (or e-mail): (EMAIL):GERARD AT ASTRO.ULG.AC.BE (FAX):3
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Name:                                                      Category: CON
Institution:
Address:
City:                                           State:
Zip Code:                                       Country:
Telephone:
Telex (or e-mail):
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TARGET LIST    b)Solar System Targets                                                              ID = 5341             [  5]
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TARGET NUMBER:    1    |    TARGET NAME: LIMBSAT
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TARGET DESCRIPTION: FEATURE SATURN
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           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    STD = SATURN                                              |    TYPE=TORUS, LONG=0,LAT=34.5,
                                                              |    RAD=58187,POLE_LAT=90
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
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REF | DATA                                                    |            COMMENTS
    |                                                         |
    |                                                         |    THIS PROGRAM SHOULD PREFERABLY TAKE
    |                                                         |    PLACE CLOSE TO OPPOSITION . CENTER
    |                                                         |    OF FOV SHOULD BE POINTED ON THE
    |                                                         |    PLANETARY SPIN AXIS, TOWARDS NORTH
    |                                                         |    POLE, TO THE PLANETOGRAPHIC PARALLEL
    |                                                         |    EQUAL 40D NORTH
                                                              |
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TARGET NUMBER:    2    |    TARGET NAME: SATNORTH1
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TARGET DESCRIPTION: FEATURE SATURN
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           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    STD = SATURN                                              |    TYPE=TORUS, LONG=0,LAT=34.5,
                                                              |    RAD=58187,POLE_LAT=90
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           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    CML OF SATURN FROM EARTH
                                                              |    BETWEEN 120 200
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REF | DATA                                                    |            COMMENTS
    |                                                         |
    |                                                         |    THIS PROGRAM SHOULD PREFERABLY TAKE
    |                                                         |    PLACE CLOSE TO OPPOSITION . CENTER
    |                                                         |    OF FOV SHOULD BE POINTED ON THE
    |                                                         |    PLANETARY SPIN AXIS, TOWARDS NORTH
    |                                                         |    POLE, TO THE PLANETOGRAPHIC PARALLEL
    |                                                         |    EQUAL 40D NORTH
                                                              |
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EXPOSURE LOGSHEET                                                                                  ID = 5341             [  6]
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 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
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  Line  |  Seq  |   Target  |Instr | Oper. | Aper  |Spectral|Central|   Optional    |Num|  Time |   S/N   |Flx|Pr|     Special
 Number | Name  |    Name   |Config| Mode  |or FOV |Element |Waveln.|  Parameters   |Exp|       |Rel. Time|Ref|  |   Requirements
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1        DEFINE  #           FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     1   900S                  #  CYCLE 4
         ORBIT                              4       F175W            CHECK-
                                                                     FILTER=YES
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2                LIMBSAT     FOC/96 IMAGE   512X102 F210M,           PIXEL=50X25     1   1000S                 1  CYCLE 4
                                            4       F220W,           CHECK-                                       PCS MODE F / 2-10
                                                    F2ND             FILTER=YES                                   BEFORE 3 BY 96M +/
                                                                                                                  - 20M
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3        USE     SATNORTH1                                                                                     1  SEQ 3-10
         ORBIT
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4        USE     LIMBSAT                                                                                       1  AFTER 3 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 3
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5        USE     LIMBSAT                                                                                       1  AFTER 4 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 4
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6        USE     LIMBSAT                                                                                       1  AFTER 5 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 5
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7        USE     LIMBSAT                                                                                       1  AFTER 6 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 6
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8        USE     LIMBSAT                                                                                       1  AFTER 7 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 7
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9        USE     LIMBSAT                                                                                       1  AFTER 8 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 8
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10       USE     LIMBSAT                                                                                       1  AFTER 9 BY 96M +/-
         ORBIT                                                                                                    20M
     Comments: EXPOSURE  TAKEN 1 HST ORBIT
               AFTER EXPOSURE 9
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            Summary Form for Proposal 5341                                                                               [  7]

  Item                          Used in this proposal
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  Configurations                FOC/96
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  Opmodes                       IMAGE
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  Optional Parameters           PIXEL= 50X25 CHECK-FILTER=YES
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  Proposal for                  GO
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  S/C Hours                     3.00
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  Scientific Category           SOLAR SYSTEM
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  Scientific Sub-category       GIANT PLANETS
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  Special Requirements          CYCLE 4; PCS MODE F / 2-10; BEFORE 3 BY 96M +/- 20M; SEQ 3-10; AFTER 3 BY 96M +/- 20M ; AFTER 4 BY
                                96M +/- 20M ; AFTER 5 BY 96M +/- 20M ; AFTER 6 BY 96M +/- 20M ; AFTER 7 BY 96M +/- 20M ; AFTER 8 BY
                                96M +/- 20M ; AFTER 9 BY 96M +/- 20M ;
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  Spectral Elements             F152M,F175W F210M,F220W,F2ND
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  Target Names                  LIMBSAT SATNORTH1
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