Page   1
    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID 4608c
                                                       Report Date: 09-May-96:19:44
                                                       Version: **********
                                                       Check-in Date: **********

1.Proposal Title:
MULTI TIMESCALE MULTISPECTRAL OBSERVATION OF THE JOVIAN AURORA  CYCLE3 HIGH
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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
Prof Jean-claude Mc Gerard  UNIVERSITE DE LIEGE            BELGIUM    32-41-529980
RESEARCH DIRECTOR
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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. They and
other IUE and Voyager UVS observations suggest that wavelength dependence and time
variations occur with different characteristic times.  We propose to image the
ultraviolet jovian aurora in several passbands to investigate its temporal variation
on timescales ranging from ~10 min to hours.  Exposures will be made when the 180
deg (Lambda III) longitude sector, where the aurora is best visible from Earth
orbit, faces the Earth.  Due to the expected loss of sensitivity in the far UV, this
program should be preformed before the COSTAR correction. Coordinated IR
measurements of emission connected to the UV aurora but originating from different
altitude regions will be obtained in parallel with HST observations.  Simultaneous
radio observations of decametric jovian emissions and IUE UV spectra will also
provide complementary data on energetic particle precipitation. The observed
morphology, color ratio and characteristic time of the temporal variations will
provide key information to discriminate between the  various origins , identity and
acceleration mechanisms of the precipitating particles.  Theoretical models of
particle interaction with the jovian magnetic field and atmosphere available from
the proposing team will be used to derive quantitative information on these
processes.
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8. Scientific Key Words:   GIANT PLANETS, UV AURORA, H2, LYMAN-ALPHA
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9. Est obs time (hours) pri: 6.60     par: 0       10. Num targs pri: 1      par: 0
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11. Instruments requested:  FOC
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12. Special sched req:  Time Critical obs.
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                                                                  Page   2
I. GENERAL FORM    Proposal 4608c
PI: Prof Jean-claude Mc Gerard
Proposal Title:
MULTI TIMESCALE MULTISPECTRAL OBSERVATION OF THE JOVIAN AURORA  CYCLE3 HIGH
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1. Proposers:
Proposers                        Institution                       Country       ESA
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Pr Jean-Claude Mc Gerard         4330                              BELGIUM        X
Dr Gilda Ballester               2380                              USA
Dr Lotfi Benjaffel               5436                              FRANCE         X
 Vincent J. Dols                 4330                              BELGIUM        X
Dr Francesco Paresce             3470                              USA            X
Dr Renee Prange                  5448                              FRANCE         X
 Daniel Rego                     5448                              FRANCE         X
Dr Hunter J. Waite               3440                              USA
Dr Alex D. Storrs                3470                              USA
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  2. Scientific Justification.
  The jovian polar aurora in not only one of the most fascinating phenomena in the
 solar system, it has recently become, through the possibility of UV imaging with
 the HST and infrared observations from the ground, one of the key scientific
 fields where new, carefully planned observations will provide important insight.
 As with other planets , jovian aurorae are the visible signature of the coupling
 between the magnetosphere and the planets' atmospheres.  For the outer planets
 which can rarely be visited, they provide a unique tool for the study of the
 magnetosphere, the effect of the solar wind and/or the planetary rotation on its
 dynamics and energetics, the satellites as plasma sources and energetic particle
 sinks and the global electrodynamical convection patterns coupling the
 magnetosphere and the ionosphere.  Based on the terrestrial example and on
 specific studies of the Jovian magnetosphere (the few in-situ data from Pioneer,
 Voyager and Ulysses and theoretical work), several candidate processes have been
 identified for driving the Jovian aurorae and these can either dominate or
 coexist: - precipitation of magnetospheric particles (electrons, protons, and/or
 ions) pitch-angle diffused by e.m. waves in the Io plasma torus (diffuse aurora)
 - precipitation of particles, mainly electrons, accelerated by potential drops
 along magnetic field lines connected to various regions of the magnetosphere
 where intense field-aligned currents can flow (Io flux tube, plasma disc, outer
 magnetosphere field lines reconnecting to the solar wind (discrete aurorae) -
 precipitation of solar wind particles either directly into the cusp or soon
 after injection in the magnetosheath and/or the boundary layer (giving either
 diffuse or discrete aurorae). The characteristics of the resulting auroral
 emissions must be different and bear the signature of the precipitation
 processes.  In particular: - they differ in their morphology (forming ovals or
 only arcs at different latitudes, connected to Io, to the Io plasma torus, to the
 middle or the outer magnetosphere, or even extending into the polar cap, and
 looking as diffuse or discrete emissions) and by the energy/penetration depth of
 the precipitating particles (up to 100 kev or about MeV/nucleon if electrons or
 ions diffused by e.m.  waves, keVs to tens of keVs if accelerated by electric
 fields, 100eVs to keVs if coming from the solar wind or the boundary layers). -
 they differ in the timescale of their temporal variations (timescales of months
 for the plasma torus, of days or fractions of day for the pitch angle diffusion,
 of hour(s) for the solar wind control, and down to a few minutes for field
 aligned currents generating acceleration structures and discrete aurorae) - they
 differ in the associated emissions in various other wavelength ranges:
 radioemission is only excited by keV electrons in acceleration structures and the
 electron bremsstrahlung spectrum differs from heavy ion X ray lines (only
 observed for ion pitch angle diffusion), extremely intense IR emission can be
 expected to be due to Joule heating from field aligned currents. The morphology
 of the Jovian UV aurora is now the best documented aspect of this research field.
 The paradigm derived from the limited spatial resolution/ non imaging
 observations of Voyager and IUE was that of two emitting rings   surrounding the
 north and south poles, confined within an oval close to the Io orbit footprint
 (north 'UVS oval', Broadfoot et al., 1981), or at slightly higher latitude
 (6<L<12, Livengood et al., 1992), presumably not reaching the poles.  Along this
 oval, the intensity is strongly modulated, with maxima at 195+/-30 deg (north)
 and 20+/-40 deg (south) (Herbert et al., 1987;  Livengood et al., 1992). Imaging
 of the UV aurora was first performed with the FOC in February 1992, during the
 Ulysses flyby, in the Werner and Lyman bands of H2 and at Lyman-alpha (Gerard et
 al., 1992, Dols et al., 1992;  Waite, 1992;  Caldwell et al., 1992). These
 observations open a new era of discoveries where key scientific issues concerning
 the morphology, the physical processes of solar wind - magnetosphere - atmosphere
 interactions may be addressed with a new powerful tool. The earlier picture was
 confirmed on the average, including the brightness , although the peak emission
 in the north was, on the average, at a lower longitude (145-170 deg) and the 180
 deg meridian looked as a minimum. These exploratory images, however, were only
 taken when the expected emission peak region faced the Earth (115 deg<CML<200
 deg).  Mapping of the auroral ovals over a complete Jovian rotation is clearly
 necessary to study the 'backside' of the aurora , to model the contribution of
 the emission at or slightly behind the limb to the emission from the front side,
 and to disentangle the effect of the viewing geometry on the aspect of the
 auroral oval (real polar extent, limb brightening).  Such observations are
 scheduled for the coming year of GTO programs (Paresce,PI; Caldwell,PI) and do
 not need to be repeated in Cycle 3.   The images obtained at Ly-alpha (Gerard,
 1992;  Dols et al., 1992, Prange et al., 1992) exhibited some significant
 differences with the images obtained at the same period in the H2 We-Ly (Waite,
 1992;  Caldwell,1992).  In particular, the Ly-alpha emission looks broad,
 covering part of the polar region, whereas the H2 aurora is mostly confined to a
 narrow arc.  Differences also exist between the peak emission longitude in the Ly
 and We bands, still under study. The former effect can be due to the dependence
 of the excitation cross section on the species and energy of the impinging
 particles, to the different altitude distribution of H and H2, and to radiative
 transfer effects at Ly-alpha.  It has been thoroughly modeled (Gerard and
 Singh,1982;  Waite et al.,1983;  Horanyi et al.,1988;  Rego et al., 1992;  Prange
 et al., 1992, Ben Jaffel et al., 1988), and can be used as a diagnostic of the
 precipitating particles.  The latter effect can be due to absorption by the
 overlying CH4 whose cross section is larger for the We bands than for the Ly
 bands.  Livengood et al.(1990) have shown that the particle penetration depth
 (and hence their energy) can be derived from the observed ratio I(Ly)/I(We), and
 that this variable ratio is generally maximum with the input flux.  Therefore,
 much can be learnt on the various mechanisms responsible for the auroral
 excitation at the various locations already identified, provided images are taken
 at various wavelengths (HLy alpha, H2 We and Ly) nearly at the same time.
 Simultaneity of the observations is an important condition since temporal
 variations of the FUV emissions have been recorded at widely different
 timescales. The analysis of the Voyager and IUE data (ten years of data) suggests
 that the   major features of the Jovian aurorae are rather stable with however
 global variations of the brightness by a factor of 2-3 and shifts in the
 longitude of the peak as large as 40-50 deg on periods of months.  A new image in
 the H2 Ly bands taken in June 1992 (Gerard et al., 1992, Prange et al., 1992)
 confirms the long-term variability of the aurora.  Although the analysis is still
 in progress, it is clear that important differences are seen between the 2 sets
 of images:  dawn-dusk asymmetry observed in February 1992 is absent, two bright
 spots are seen instead of one , one of them close to 190 deg which was a minimum
 in February (see enclosed figure).  Such a variability was also observed within a
 few days (Herbert et al.,1987) and even a fraction of day, as in the case of an
 exceptional event recorded with IUE (Livengood et al., 1991).  However, due to
 the scarceness of the observations, the real timescale is still unknown.  In
 addition, the Jovian aurora looks as a collage resulting from different
 processes, as suggested by the recent HST images.  It is therefore absolutely
 necessary to investigate whether these various timescales apply to the whole
 aurora or to individual features only.  Based on the first FOC-HST data, the only
 ones to allow mapping in the UV, such significant variations do not seem to occur
 on short timescales in the north:  successive images of the Ly alpha aurora show
 that the main high latitude arc and the low latitude bright spot are stable and
 corotating with the planet.  In contrast, there are indications of smaller
 features appearing or disappearing in less than 1.5 hours (Prange et al.,1992),
 and perhaps of bursty emission with timescale in the 10 mn range   (Waite, 1992).
 Finally, auroral emissions in other wavelength ranges are also present:  in the
 near IR (H2 and H3+ at 2 and 4 microns), the mid IR (hydrocarbon from 8 to 13
 microns), the X rays, and the radioemissions (decametric to kilometric), but
 their connection with the UV is not yet clearly understood.  The recently
 discovered near IR emission (Drossart et al.,1989) are essentially thermal
 (indirectly monitoring energy input), but they can also reflect increased [H3+]
 by particle precipitation.  The very first Protocam images (Ballester et
 al.,1991;  Baron et al.,1991;  Drossart et al.,1992) suggest similarities between
 the H3+ aurora and the UV one as mapped by HST.  The H3+ aurora is also very
 variable even on timescales of minutes (Baron et al., 991;  Kim et al .,1992).
 The hydrocarbon aurora, especially the methane one, are also thermal and excited
 deeper in the atmosphere than the UV and H3+ aurorae.  Prange (1991) and Drossart
 et al.(1992) have established that it is located on about the same auroral oval
 than UV ('UVS') and H3+ emission.  However, a significant difference is that it
 is restricted to a single, rather stable, bright spot at 180 deg.  within +/- 20
 deg in the north (Caldwell et al.,1988;  Kostiuk et al.,1992).  X ray auroral
 emission have been recorded twice and the analysis of their spectrum seems to
 favor an excitation of oxygen and/or sulfur ions (Metzger et al ., 1983;  Waite,
 1992) indicative of precipitation by pitch angle diffusion.  However, this
 emission could be related to one aspect of the auroral phenomenon only since
 significant radioemission (exclusively related to electron cyclotron emission in
 discrete arcs) are also regularly recorded.  Two sources   at least are
 identified, one at the footprint of the Io flux tube ('Io controled'), and the
 other, 'non-Io', on high magnetic field lines, L>15 (Ladreiter and Leblanc,
 1990?).  Both sources are modulated in longitude with a maximum in the same
 region as the UV maximum.  The non Io source is variable, and correlated with the
 solar wind activity.  Correlations between the decametric emission (routinely
 observed from the ground) and the UV one is very difficult, due to the specific
 conditions of the radio propagation and the lack of spatial resolution.  However,
 a correlated event was first detected in December 1990 (Prange et al., 1992b),
 providing new insights on the Jovian auroral mechanism(s). Consequently, we plan
 to take advantage of the high spatial resolution of the FOC which will allow
 meaningful localized comparison between the H-Ly alpha, the We and the Ly H2
 emission and existing one dimensional models.  The variability of the various
 spatial auroral features, already identified on various magnetic field lines by
 earlier mapping, will be investigated on several timescales representative of
 various magnetospheric processes from tens of min to weeks. In addition,
 correlated observations at a comparable spatial resolution will be performed in
 the near- and mid-IR for comparison of localized spatial structures and of their
 variability.  Finally, the temporal variations of the decametric radioemission,
 routinely recorded from the ground will be compared to variations of the discrete
 auroral features. Time for a parallel campaign of Jovian auroral observation with
 IUE has also been requested. In summary, we propose a short,time-effective
 program to image the UV aurora simultaneously with coor-   This set of
 observations will allow to identify the different components of the Jovian
 aurora, to characterize the magnetospheric processes and thereby to construct a
 global picture of this fascinating phenomenon . References ---------- Ballester,
 G.E., R.  Prange, S.  Kim, T.  Livengood, H.W.  Moos, and J. Caldwelbt 1991, .
 Sandel, and A.L.  Broadfoot, 1987, J.  Geophys.  Res., 92, 3141 Horanyi, M., T.E.
 Cravens, and J.H.  Waite, Jr., 1988, J.  Geophys.  Res., 93, 7251 Kim, S.J., J.
 Caldwell, and T.M.  Herbst,1992, Icarus,96, 143 Kostiuk, T., P. Romani, F.
 Espenak, T.  Livengood, and J Goldstein, "Variable Phenomena in Jovian Systems",
 Annapolis, 23-26 july 1992 Ladreiter, H.P., and Y.  Leblanc, 1990, J.  Geophys.
 Res., 95,6427 Livengood, T.A., D.F.  Strobel, and H.W.  Moos, 1990, J.  Geophys.
 Res., 95, 10375 Livengood, T.A., R.  Prange, G.E.  Ballester and W.H.  Moos,
 1991, EOS, 72, 186 Livengood, T.A., H.W.  Moos, G.E.  Ballester, and R.M.
 Prange, 1992, Icarus, 97,26 Prange, R., 1991, Astron.  Astroph., 251, L15 Prange,
 R.  and M.  Elkhamsi, 1991, J.  Geophys.  Res., 96, 21371 Prange, R., D.  Rego,
 and J.C.  Gerard, 1992, submitted for publication. Prange, R., V.  Dols, J.C.
 Gerard, and F.  Paresce, 1992a, in "Variable   Phenomena in Jovian Systems",
 Annapolis, 23-26 july 1992. Prange, R., P.  Zarka, G.E.  Ballester, T.A.
 Livengood, H.W.  Moos, and L. Denis, 1992b, "Variable Phenomena in Jovian
 Systems", Annapolis, July 1992, to be submitted to J.  Geophys.  Res. Rego, D.,
 R.  Prange, and J.C.  Gerard, 1992, submitted for publication. Waite, J.H.,Jr.,
 T.E.  Cravens, J.  Kozyra, A.F.  Nagy, S.K.  Atreya, and R.H. Chen, 1983, J.
 Geophys.  Res., 88, 6143 Waite, H.  Jr., 1992, paper presented at "Variable
 Phenomena in Jovian Systems", Annapolis, 23-26 july 1992
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  3. Description of proposed observations.
  As described in the scientific justification, we plan to investigate the time
 variation of the jovian aurora at different timescales and wavelengths by taking
 advantage of the FOC filter combinations and coordinating with parallel IR and
 radio ground observations. As far as the HST observations are concerned, this
 objective will be realized by imaging the jovian northern auroral zone with the
 FOC using the F/96 relay using the zoomed pixel format (8-bit words, 22 x 22
 arcsec) to increase the visibility of the the aurora.  Previous experience has
 demonstrated that the count rate is low enough to prevent 8-bit word
 saturation.OOB The aurora will be imaged at Lyman alpha, and in the Werner and
 Lyman bands of H2 using combinations of filters which adequately isolate the
 desired wavelength ranges: F120M+F140W, F130M+F140W and F152M+F175W,
 respectively. These combinations were already successfully used in GTO program
 1269 and DDP4005. Sequences of exposures will be repeated with various
 periodicities to check systematically the variability of the north aurora versus
 several magnetospheric time scales: 1-2 hours (from one orbit to the next), 10-15
 hours (over one Jovian rotation), and days- weeks. The shortest timescales of
 minutes suggested by previous observations will be checked in a single wavelength
 range (H2 Lyman) by successive exposures taken on the same orbit (2 exposures
 within about 1/2 hour). Since the global morphology will be known at that time
 well enough to allow us to fully analyze the limb brightning effect and the
 possible contributions from the back side of the auroral oval, we will compare
 images of the same   selected longitude sector of Jupiter where the aurora has
 proven to be most active. The CML will be fixed at 180 deg +/- 58 deg (Jupiter
 rotation during one HST period) for the central exposure of each sequence, the
 individual features in the images being easy to localize within about 60 deg.
 from the central meridian. Additional short exposures with a suitable set of
 filters will be made on the first two visits to locate accurately the limb of the
 planet and cross check the limb determination derived during each sequence from
 the H2 Lyman images. This program will be implemented as follows: 1. During 4
 CONSECUTIVE HST orbits, a.  A continuum image will be made using the
 F210M,F220W,F6ND filters SIII Central Meridian Longitude = 70 deg. b.  A first 15
 -min. FOC exposure with the F152+F175W filters (H2 Lyman-bands) will be obtained
 when the SIII Central Meridian Longitude = 130 deg. c.  During the next orbit,
 two consecutive 15-min. exposures will be made,  through the same filter
 combination . SIII CML will be near 190 deg. and 200 deg. respectively. Data
 collected  during the 3 HST orbits will reveal the importance and features   of
 the time variation of the precipitation pattern and/or magnetospheric variation
 of the precipitation pattern and/or magnetospheric processes on the time scales
 of 15 min. and 1-2 hours. 2.  The same sequence 1a-c is repeated during the
 following jovian rotation, that is ~10 hours later but with the filter
 combination F120M+F140W ( HI Ly-alpha) and CMLs as close as possible to those of
 sequence 1. 3.  Sequence 1b-c is repeated during the next jovian rotation with
 filters F152M+F175W and for CMLs as close as possible to sequence 1 4.  Sequence
 1b-c is repeated during the next jovian rotation with filters F130M+F140W (H2
 Werner-bands) with CMLs as close as possible to sequence 1. The sequences 1,2,3
 and 4 will provide the multispectral imaging together with information concerning
 the 15-min, 1-2 and 10 hour variability of the jovian aurora. Revised 4 Feb. 1993
 to include FOC bright object observation safety procedures. Contact Alex Storrs
 (STScI, storrs@stsci.edu, 410-338-4903) with questions.
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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 jovian aurora.  In fact, the ability of HST to provide
 images of the aurora of Jupiter may be considered as one of the major
 accomplishments of the HST in planetary sciences 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 magne
 tospheric environment and physical processes.  Previous FOC/HST observations in
 the GTO ULYSSES encounter program have demonstrated the ability of HST to monitor
 the spatial distribution of auroral phenomena from Earth orbit. However, no
 systematic information has ever been gathered concerning the time variation of
 the jovian aurora and the time constants involved in the physical processes
 controling particle precipitation.  Only hints that such variations exist were
 provided by IUE and Voyager UVS spectrometer observations with very crude spatial
 resolution.  Ground-based infrared observations also suggest the existence of
 time variations but they could not have been related to the UV aurora until HST
 UV imaging became possible. This program provides a unique opportunity to
 accomplish a major step towards the understanding of the jovian magnetospheric
 physics using an approach whose feasibility has now been clearly demonstrated.
 The parallel ground-based IR and radio observations will provide key information
 extremely useful in understanding future IR observations and their relation to
 the UV aurora. As shown by previous HST imaging of the same target, the
 aberration problem of   the HST does not prevent obtaining good quality auroral
 observations. The amount of exposures requested in this program is the best
 possible compromise between the need to obtain as many images of the same auroral
 sector as possible and the limits on the spacecraft time available.  Only one
 object (the northern polar region of Jupiter) is requested and use is made of the
 planet's rotation and HST orbit to obtain time sequences of the auroral
 phenomenon.  The exposure times are based on observational experience with the
 same filters combinations obtained during our and other previous observations of
 the same object (GTO program 1269, DDP 4005).  They are limited on one side by
 the need to obtain a sufficient S/N ratio and, on the other side, on the limits
 to spatial resolution set by the planet's rotation during the exposures. Pictures
 shown before demonstrate that good quality data may be collected with this
 observational and instrumental configurations. For example, previous 20 min Ly-
 alpha exposures (F120M + F140W) provide a S/N ratio of about 4.  Previous H2 Ly-
 bands 15 min exposures (F152M + F175W) were obtained with a S/N of nearly 10.
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  5. Description of special scheduling requirements.
   A coordinated campaign involving simultaneous observations with IUE has been
 planned for 1993. If possible, this program should be scheduled within one of the
 IUE windows, preferably before 17 July 1993.
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  7. Data reduction and analysis plans.
  The set of co-investigators of this program covers all fields of expertise
 needed to collect and process the data, analyze the images and make a thorough,
 in-depth study of their significance and implications in the field of Jupiter'
 magnetospheric and atmospheric sciences.  The PI and most Co-Is have a wide
 scientific experience in the fields of planetary atmospheres and magnetospheres
 and image processing.  They have published a large number of scientific papers in
 international refereed journals.  More specifically, the plans for data reduction
 and analysis are as follows. 1) The observations will be obtained and processed
 under the lead of the PI with active participation by Dols, Paresce, Storrs who
 have experience with the FOC and auroral UV observations and the STScI data
 pipeline and support and have already successfully analyzed FOC images of Io and
 of the Jovian aurora from GTO 1269 program (see list of publications). In
 addition to the procedures develloped at the PI's institutions,various IDL
 procedures have been developed by G.E.  Ballester and J.H. Waite's to analyze
 HST, IUE and IR (Protocam images) observations.  Other ones will be developed as
 needed by the program. Since the discovery of the spherical aberration, we have
 been especially concerned with the numerical deconvolution methods.  Several
 methods are currently implemented on our workstations and have successfuly been
 used for the restoration of Io images in the GTO 1269 program. 2) One of the
 major problem in comparing images taken at different time (i.e.   with different
 guide stars) and in comparing UV images with IR images, will be the accuracy
 obtained in the location of the auroral features, which must reach a fraction of
 arcsec. This issue is addressed by the presence of the combination of filters
 152M+175W which shows the limb of the planet as seen in previous GTO images at
 this wavelength). This will be improved by a few visible image during the
 observing sequence.  In any case, the analysis needs experience in limb fitting
 G.E.  Ballester has developed this expertise from the analysis of IR Protocam
 images. The retrieved images will then be analyzed for any effects such as limb
 darkening and/or limb brightning at the various wavelengths, including resonant
 scattering at Lyman alpha, with already developed codes (L. BenJaffel and D.
 Rego). The contribution of emission from the backside of the auroral oval at the
 limb or just behind the limb will be modeled using the global representation of
 the north aurora derived from our GTO program (mapping of the aurora over a whole
 jovianain rotation, to be scheduled). 3) Once processed and analyzed, the HST
 images will be compared at various wavelength and their characteristic spatial
 features, their differences if any, and their temporal variations will be
 theoretically interpreted. Several numerical models were developed by the PI and
 Co-Is to analyze and model planetary auroral observations: - a code for
 generating synthetic spectra of the H2 bands and continuum in the 1100-2000 A
 range and their calculating their transmission through the   FOC UV filters has
 been developed at the P.I.'s institution.  It will be used to convert the
 measured count rate into total H2 emission rates. - modeling of multiple
 wavelength emissions (R.Prange, D.Rego,J.H.Waite, J.C. Gerard), including
 altitude distribution of the excitation by energetic particle and absorption by
 hydrocarbons and color ratio calculations - calculations of energetic particle
 interaction with Jupiter's atmos phere and iterative modeling of the Jovian
 atmosphere (providing a reliable auroral atmospheric model to be used in the
 previous calculations) have been developed and are still being improved (H.
 Waite) - radiative transfer analysis of UV emissions in an optically thick
 atmosphere (L. Ben Jaffel, D. Rego) - model of the longitudinal distribution of
 the energy deposition rate which we expect to derive informations on the
 injection mechanism of the particles, their equatorial distribution, the ratio of
 the electrons/ion input flux and to put new constrains on the ground level
 magnetic field (R. Prange) 4) Parallel IR and radio DAM data will be obtained
 through Co-Is G.E. Ballester, R.  Prange, and H.W.  Waite.  Two of them
 (Ballester and Prange) have already a several years experience in the
 organization and analysis of correlated IR/UV observing campaigns between
 IRTF(Hawaii) and IUE (see references in the scientific justification).  They have
 also developed collaborations with IR observers from the major observatories.
 Prange has also developed expertise in the analysis of radio emission and their
 correlations with UV data from IUE (see scientific justification).  Prange and
 Waite can   bring collaborators in the field of radio observations and modeling
 from France, US, and Japan. 4) The PI will have the overall responsibility to
 obtain the data, analyse them, coordinate a fast and efficient analysis and
 publish them in the scientific literature.
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  8. Additional comments or special requests.
  As briefly described in (2) and (14), ground based IR and radio observation will
 be made in parallel with the HST observations.  The Workshop "Variable Phenomena
 in Jovian Systems" held in Annapolis (22-26 July 1992) has adopted, on behalf of
 the International Jupiter Watch, a recommendation to encourage and facilitate the
 correlated multiwavelength observations of the Jovian aurorae.  This will make
 the simultaneity of the HST observations with ground-based IR observations easier
 to schedule.  However, a problems remains, due to the fact that IR observations
 are only possible at night.  To increase the temporal coverage of the IR
 observations and get a good overlap with the HST observing sequences (about 13
 hours each), observatories located at different longitudes must be involved in
 the program.  This can be reached using the Hawaii telescopes CFHT, UKIRT and
 IRTF, with which G.E.  Ballester and R.  Prange have already collaborated (P.
 Drossart, T.  Kostiuk, S.  Miller, among others, are willing to collaborate on
 this new program on the various Hawaii instruments) and the Pic du Midi
 Observatory (France) where R.  Prange has already been observing, and which will
 be equipped with a new near-IR camera at the time of the Cycle 3 observations.
 For the radio observations, the problem of correlated observations is much less
 critical, since several radio-observatories make routine observations of the DAM
 Jovian emissions. In order to get a 24 hours coverage, data from various
 observatories will be used. R. Prange can have access to the French Nancay DAM
 array database (in collaboration with Y. Leblanc, A. Lecacheux, P. Zarka), and
 has developed collaborations with the observatory of the University of Florida
 (T. Carr). H. Waite will have access to US and Japanese data.
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  9. Description of previous HST work.
  1.  GTO program 1269, Far UV imaging of the Giant Planets (F.  Paresce, PI; J.C.
 Gerard, Co-I) is partly related to this project.  GTO results on the mapping of
 the jovian Ly-alpha and H2 aurora will be used as a basis on which this program
 and its physical analysis will be built.  However, the GTO observations are
 widespread in time and will NOT provide the time coverage needed to analyze time
 variations.  It does not either provide the multispectral data.  UV and visible
 images of Io's surface were also obtained in this program. 2.  Discretionary time
 (ID 4005),"HST UV Imaging of Jupiter to Support the Interpretation of Ulysses X-
 Ray Measurements" was provided during the ULYSSES spacecraft encounter with
 Jupiter (Stern, PI; Waite, Co-I) to image the H2 aurora in the Werner bands and
 for comparison with in-situ particle and field measurements. 3.  GTO/FOC 1253,
 High Resolution Observations of Cataclysmic Variables (F. Paresce, PI);  Not
 Related 4.  GO 3511, H Ly alpha dayglow emission line profiles for the outer
 planets, J. Clarke, PI;  R.  Prange, L.  Benjaffel, Co-Is);  Not Related 5.  GO
 2627, Io's atmosphere and its interaction with the plasma torus (H.W. Moos, PI,
 G.  Ballester, Co-I);  Not Related   1.  Cycle 0 GTO 1269 images were  taken in
 1991 and 1992.  Io was observed through several combinations of filters from
 F120M to F220M.  These images show SO2 frost patches on the surface of Io and are
 currently beeing compared with Voyager images taken 12 years ago.  Extended
 deconvolution has been applied to these images, which should be very useful for
 the image processing of the Jovian aurora images. 2.  Auroral images obtained
 during GTO cycle 1 (1992) provided the first UV picture of the northern polar
 jovian aurora.  Two Lyman-alpha images of the north polar region of Jupiter were
 obtained with the FOC in February 1992.  The presence of high latitude regions of
 enhanced emission was clearly observed.  A comparison with the location of the
 Voyager UVS oval, the Io (L = 6) and high-latitude field-lines footprints showed
 that a better agreement is obtained with the L > 15 footprint in the sector (30
 deg.  < lambdaIII < 210 deg.) These two families of L-shells correspond to two
 possible sources of precipitation: particles originating respectively from the
 plasma torus of Io or particles from the distant magnetosphere in a distorted
 magnetic field by analogy with the terrestrial aurora.  These observations
 provided evidence that monitoring of the UV jovian aurora, its morphology and
 intensity variations can be performed from Earth orbit with the Hubble Space
 Telecope. The initial results indicate that the main auroral process is probably
 not located at the footprint of the theoretical Io footprint, in contrast to the
 view widely accepted so far.  They suggest that the emission could take place on
 high latitude field lines and that the stucture of the brightest features is
 patchy, exhibiting large longitudinal inhomogeneities. An excellent set of H2
 images, presently being analyzed, was also obtained in June 1992 at 160 nm
 (Paresce et al.) and, with a lower S/N, at 130 nm (Stern et al.).  These images
 confirm the result indicated before:  the auroral oval lies on the footprint of
 distant magnetic field lines originating from the middle and/or outer
 magnetosphere of Jupiter. 3. GO 3511: first observations will be made after cycle
 3 submission deadline Io surface ultraviolet imaging with the HST Near UV imaging
 of Jupiter's satellite Io with HST, Astron.  Astrophys, 1992, in press. Far
 ultraviolet imaging of the jovian aurora with the Hubble Space Telescope V. Dols,
 J.C.  Gerard, F.  Paresce, R.  Prange and A.  Vidal-Madjar, Geophys.  Res. Lett.,
 1992, in press. Solar system observations with HST, F. Paresce and J.C. Gerard,
 in Proceedings of the International Space Year Conference Munich, 1992, in press.
 Far ultraviolet imaging of Jupiter's northern polar regions with the FOC J.C.
 Gerard, V. Dols, F. Paresce, R. Prange and A. Vidal-Madjar, Proceedings of the
 HST Workshop, Sardinia, 1992, in press.   High resolution near UV observation of
 Jupiter's satellite Io with the HST, F. Paresce, P. Sartoretti, V. Dols, J.C.
 Gerard and M. McGrath, Proceedings of the HST Workshop, Sardinia, 1992, in press.
 First Results from the FOC:  Imaging the Core of R Aqr, F.  Paresce et al.,Ap. J.
 Lett., 369, L67, 1991 The Structure of the Inner Arcsecond of R Aqr observed with
 HST, D.Burgarella and F.Paresce, Ap. J. Lett., 389, L29, 1992 Blue Stragglers in
 the Core of the Globular Cluster 47 Tuc, F.Paresce et al., Nature, 232, 297, 1991
 High resolution near UV observation of Jupiter's satellite Io with the Hubble
 Space Telescope, V.  Dols, J.C.  Gerard, P.  Sartoretti, H.-M.  Adorf and F.
 Paresce, Abstract of a 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., presented at the EGS General Assembly,
 Edingburgh, April 1992. Multispectral Observations of Jovian Aurora, H.  Waite et
 al., paper presented at the UCLA conference, June 22-26 and at the Variable
 Phenomena in Jovian   Planetary Systems, Annapolis July 13-16. Analysis of the
 first image of the the jovian aurora at Lyman alpha obtained with the HST, R.
 Prange, V.  Dols, J.C.  Gerard and F.  Paresce, paper presented at the conference
 "Variable phenomena in jovian planetary systems", Annapolis, July 13-16.
 Observations of the H and H2 ultraviolet aurora with the HST Faint Object Camera
 , J.C. Gerard, V. Dols, F. Paresce and R. Prange, abstract, 1992 DPS meeting,
 Munich, 1992, in press.
                                                                  Page   9
------------------------------------------------------------------------------------
 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 program) funded by the Belgian
 Government for HST data analysis -1 graduate student in plasma physics (France) -
 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
 (see budget in annex).
------------------------------------------------------------------------------------
11. Address Information
Name:  JEAN-CLAUDE M GERARD                                Category: PI
Institution: INSTITUT D ASTROPHYSIQUE
Address:  5, AVENUE DE COINTE
City: LIEGE                                     State:
Zip Code: 4000                                  Country: BELGIUM
Telephone: 32-41-529980
Telex (or e-mail):
------------------------------------------------------------------------------------
TARGET LIST    b)Solar System Targets                                                              ID = 4608c            [ 10]
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    1    |    TARGET NAME: JUPITER-OFF
------------------------------------------------------------------------------------------------------------------------------------
TARGET DESCRIPTION: FEATURE JUPITER
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    STD=JUPITER                                               |    TYPE=POS_ANGLE,RAD=65,ANG=102,
                                                              |    REF=NORTH
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
REF | DATA                                                    |            COMMENTS
    |                                                         |
    |                                                         |    POSITION IS 63" V3 FROM DESIRED.
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
TARGET NUMBER:    2    |    TARGET NAME: JUPITER-OFF1
------------------------------------------------------------------------------------------------------------------------------------
TARGET DESCRIPTION: FEATURE JUPITER
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 1                            |            TARGET POSITION LEVEL 2
                                                              |
    STD=JUPITER                                               |    TYPE=POS_ANGLE,RAD=65,ANG=102,
                                                              |    REF=NORTH
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
           TARGET POSITION LEVEL 3                            |            WINDOWS
                                                              |
                                                              |    CML OF JUPITER FROM EARTH BETWEEN
                                                              |    120 140
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
REF | DATA                                                    |            COMMENTS
    |                                                         |
    |                                                         |    THIS PROGRAM SHOULD PREFERABLY MADE
    |                                                         |    IN JUNE 1993 WHICH IS CLOSE TO
    |                                                         |    QUADRATURE AND WITHIN THE WINDOW OF
    |                                                         |    PLANNED COORDINATED CAMPAIGN WITH
    |                                                         |    IUE. POSITION IS 63" V3 FROM
    |                                                         |    DESIRED. CML NEAR 127D  AT THE
    |                                                         |    BEGINNING OF EXPOSURE
                                                              |
------------------------------------------------------------------------------------------------------------------------------------
EXPOSURE LOGSHEET                                                                                  ID = 4608c            [ 11]
------------------------------------------------------------------------------------------------------------------------------------
 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
------------------------------------------------------------------------------------------------------------------------------------
  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
------------------------------------------------------------------------------------------------------------------------------------
9                DARK        FOC/96 IMAGE   512X102 F210M,           PIXEL=50X25     1   17S                   1  SEQ 9-12 NO GAP
                                            4       F220W,                                                        SEQ 9-10 NON-INT
                                                    F6ND                                                          CYCLE 3
     Comments: TEST EXPOSURE FOR LINE 10.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE. THE WHOLE PROGRAM
               SHOULD BE PREFERABLY SCHEDULED
               WITHIN CYCLE2
------------------------------------------------------------------------------------------------------------------------------------
10               JUPITER-OFF FOC/96 IMAGE   512X102 F210M,           PIXEL=50X25     1   900S                  1  CYCLE 3/9-42
                                            4       F220W,                                                        REQ UPLINK
                                                    F6ND
     Comments: PUT CONT. OBS. IN ORBIT BEFORE
               AURORAL OBS.
------------------------------------------------------------------------------------------------------------------------------------
10.5             DARK        FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     1   17S                   1  SEQ 10.5-11 NON-
                                            4       F175W                                                         INT
     Comments: TEST EXPOSURE FOR LINE 11.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE.
------------------------------------------------------------------------------------------------------------------------------------
11               JUPITER-    FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     1   900S                  1  REQ UPLINK
                 OFF1                       4       F175W
     Comments: THIS IMAGE DEFINES THE TIMING
               OF THE WHOLE PROGRAM
------------------------------------------------------------------------------------------------------------------------------------
12               JUPITER-OFF FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     2   900S                  1  NON-INT
                                            4       F175W
     Comments: SET OF 2 CONSECUTIVE IMAGES
               DURING THE SAME HST UNOCCULTED
               ORBIT FIRST IMAGE TAKEN 1 HST
               ORBIT AFTER BEGINNING OF
               JUPVAR11
------------------------------------------------------------------------------------------------------------------------------------
19               DARK        FOC/96 IMAGE   512X102 F210M,           PIXEL=50X25     1   17S                   1  SEQ 19-22 NO GAP
                                            4       F220W,                                                        SEQ 19-20 NON-INT
                                                    F6ND
     Comments: TEST EXPOSURE FOR LINE 20.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE.
------------------------------------------------------------------------------------------------------------------------------------
20               JUPITER-OFF FOC/96 IMAGE   512X102 F210M,           PIXEL=50X25     1   900S                  1  REQ UPLINK
                                            4       F220W,
                                                    F6ND
     Comments: IMAGE TAKEN 1 HST ORBIT BEFORE
               1ST LY A IMAGE
------------------------------------------------------------------------------------------------------------------------------------
20.5             DARK        FOC/96 IMAGE   512X102 F120M,           PIXEL=50X25     1   17S                   1  SEQ 20.5-21 NON-
                                            4       F140W                                                         INT
     Comments: TEST EXPOSURE FOR LINE 21.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE.
------------------------------------------------------------------------------------------------------------------------------------
EXPOSURE LOGSHEET                                                                                  ID = 4608c            [ 12]
------------------------------------------------------------------------------------------------------------------------------------
 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
------------------------------------------------------------------------------------------------------------------------------------
  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
------------------------------------------------------------------------------------------------------------------------------------
21               JUPITER-    FOC/96 IMAGE   512X102 F120M,           PIXEL=50X25     1   900S                  1  AFTER 11 BY 596M +
                 OFF1                       4       F140W                                                         /- 30M
                                                                                                                  REQ UPLINK
     Comments: IMAGE TAKEN 1 JOVIAN ROTATION
               AFTER 1ST H2 LY EXPOSURE
------------------------------------------------------------------------------------------------------------------------------------
22               JUPITER-OFF FOC/96 IMAGE   512X102 F120M,           PIXEL=50X25     2   900S                  1  NON-INT
                                            4       F140W
     Comments: SET OF 2 CONSECUTIVE IMAGES
               DURING THE SAME UNOCCULTED
               ORBIT FIRST IMAGE TAKEN 1 HST
               ORBIT AFTER BEGINNING OF
               JUPVAR21 EXPOSURE
------------------------------------------------------------------------------------------------------------------------------------
30.5             DARK        FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     1   17S                   1  SEQ 30.5-31 NON-
                                            4       F175W                                                         INT
                                                                                                                  SEQ 30.5-32 NO GAP
     Comments: TEST EXPOSURE FOR LINE 31.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE.
------------------------------------------------------------------------------------------------------------------------------------
31               JUPITER-    FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     1   900S                  1  REQ UPLINK
                 OFF1                       4       F175W                                                         NON-INT
                                                                                                                  AFTER 21 BY 596M +
                                                                                                                  /- 30M
     Comments: IMAGE TAKEN JOVIAN ROTATION
               AFTER 1ST LY A IMAGE SHOULD
               OBEY CML WINDOWS
------------------------------------------------------------------------------------------------------------------------------------
32               JUPITER-OFF FOC/96 IMAGE   512X102 F152M,           PIXEL=50X25     2   900S                  1  NON-INT
                                            4       F175W
     Comments: SET OF 2 CONSECUTIVE IMAGES
               DURING THE SAME HST UNOCCULTED
               ORBIT FIRST IMAGE TAKEN 1 HST
               ORBIT AFTER BEGINNING OF LINE
               31
------------------------------------------------------------------------------------------------------------------------------------
40.5             DARK        FOC/96 IMAGE   512X102 F130M,           PIXEL=50X25     1   17S                   1  SEQ 40.5-41 NON-
                                            4       F140W                                                         INT
                                                                                                                  SEQ 40.5-42 NO GAP
     Comments: TEST EXPOSURE FOR LINE 41.
               PERFORM SIP ONLY IF FILTERS ARE
               IN PLACE.
------------------------------------------------------------------------------------------------------------------------------------
41               JUPITER-    FOC/96 IMAGE   512X102 F130M,           PIXEL=50X25     1   900S                  1  REQ UPLINK
                 OFF1                       4       F140W                                                         AFTER 31 BY 596M +
                                                                                                                  /- 30M
     Comments: IMAGE TAKEN 1 JOVIAN ROTATION
               AFTER 1ST H2 LYA IMAGE OF 2ND
               GROUP (I.E. LINE 31)
------------------------------------------------------------------------------------------------------------------------------------
EXPOSURE LOGSHEET                                                                                  ID = 4608c            [ 13]
------------------------------------------------------------------------------------------------------------------------------------
 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
------------------------------------------------------------------------------------------------------------------------------------
  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
------------------------------------------------------------------------------------------------------------------------------------
42               JUPITER-OFF FOC/96 IMAGE   512X102 F130M,           PIXEL=50X25     2   900S                  1  NON-INT
                                            4       F140W
     Comments: SET OF 2 CONSECUTIVE IMAGES
               DURING THE SAME HST UNOCCULTED
               ORBIT FIRST IMAGE TAKEN 1 HST
               ORBIT AFTER BEGINNING OF
               JUPVAR41
------------------------------------------------------------------------------------------------------------------------------------
            Summary Form for Proposal 4608c                                                                              [ 14]

  Item                          Used in this proposal
------------------------------------------------------------------------------------------------------------------------------------
  Configurations                FOC/96
------------------------------------------------------------------------------------------------------------------------------------
  Opmodes                       IMAGE
------------------------------------------------------------------------------------------------------------------------------------
  Optional Parameters           PIXEL= 50X25
------------------------------------------------------------------------------------------------------------------------------------
  Proposal for                  GO
------------------------------------------------------------------------------------------------------------------------------------
  S/C Hours                     6.60
------------------------------------------------------------------------------------------------------------------------------------
  Scientific Category           SOLAR SYSTEM
------------------------------------------------------------------------------------------------------------------------------------
  Scientific Sub-category       GIANT PLANETS
------------------------------------------------------------------------------------------------------------------------------------
  Special Requirements          SEQ 9-12 NO GAP; SEQ 9-10 NON-INT; CYCLE 3; CYCLE 3/9-42; REQ UPLINK; SEQ 10.5-11 NON-INT; SEQ
                                19-22 NO GAP; SEQ 19-20 NON-INT; SEQ 20.5-21 NON-INT; AFTER 11 BY 596M +/- 30M; SEQ 30.5-31
                                NON-INT; SEQ 30.5-32 NO GAP; AFTER 21 BY 596M +/- 30M; SEQ 40.5-41 NON-INT; SEQ 40.5-42 NO GAP;
                                AFTER 31 BY 596M +/- 30M;
------------------------------------------------------------------------------------------------------------------------------------
  Spectral Elements             F210M,F220W,F6ND F152M,F175W F120M,F140W F130M,F140W
------------------------------------------------------------------------------------------------------------------------------------
  Target Names                  JUPITER-OFF JUPITER-OFF1
------------------------------------------------------------------------------------------------------------------------------------