8007(  1) - 04/16/98 14:16  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8007
                                                       Version: 1
                                                       Check-in Date: 16-Apr-1998
                                                                      14:12:42

1.Proposal Title:
The structure of the Io plasma torus: implications for energy supply
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2. Proposal For  3. Cycle
AR               7
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4. Investigators
                                                                                     Contact?
    PI: Nicholas M. Schneider             Laboratory for Atmospheric and Space
                                          Physics
   CoI: Michael Kueppers                  Laboratory for Atmospheric and Space          N
                                          Physics
   CoI: Melissa A. McGrath                Space Telescope Science Institute             N

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5. Abstract

We propose to reanalyse GHRS, FOS and WFPC2 data on the Io plasma torus in light of
new models and new theories for its energy supply. Our first goal is to use the
archival datasets to build on the 3-D torus model derived from our Cycle 5 program
(GO6027). Some of the archival observations sampled wavelengths and locations
similar to those of GO6027, allowing a rigorous search for UV variability indicative
of varying mass and energy supply. Other observations sampled different emissions
which will discriminate between several energy supply scenarios in our model. Our
second goal is a definitive test of a new theory for torus energy input which
predicts that virtually all the emission comes from a narrow region unresolved by
groundbased or Voyager observations. Measurements or upper limits from WFPC2 images
will provide a straightforward test of this hypothesis. The proposed tasks do not
repeat those proposed with the original observations, and will significantly expand
the scientific return of the original programs and our own GO program.
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  Blocking Factor: 10
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                                                8007(  1) - 04/16/98 14:16  - [  2]

            Summary Form for Proposal  8007

  Item                         Used in this proposal
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  Proposal Category            AR
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