Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5218 Report Date: 18-Jul-95:17:04 Version: ********** Check-in Date: ********** 1.Proposal Title: IO INTERACTIONS WITH THE JOVIAN PLASMA TORUS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GTO/WF2 3 Long Term yrs Sub Category SATELLITES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. John Trauger 2370 USA 818-354-9594 SCIENTIST ------------------------------------------------------------------------------------ 7. Abstract The high spatial resolution of WFPC-2 will allow an extension of groundbased observations of interactions between Io and the Jovian plasma torus. While Voyager and Ulysses spacecraft have given us in situ snapshots of the state of the torus and identified atomic and molecular species not seen from the earth, groundbased observations over a period of years have provided most of our understanding of its origin and evolution. We will use narrow-band images to observe neutral and ionized species on spatial scales smaller than the diameter of Io, just beyond the reach of groundbased observatories, in order to understand the origin and evolution of the plasma torus. HST resolution offers the unique opportunity to observe and define the `missing link' between Io's surface activity (volcanism, resurfacing, and generation of a tenuous atmosphere) and the Jovian plasma torus (which exhibits spatial structure near Io which is unresolved from the ground and variations in density and brightness on time scales from weeks to years). ------------------------------------------------------------------------------------ 8. Scientific Key Words: SATELLITE ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 2.60 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5218 PI: Dr. John Trauger Proposal Title: IO INTERACTIONS WITH THE JOVIAN PLASMA TORUS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr. John T. Trauger 2370 USA Prof. John T. Clarke 2660 USA Chris Burrows STSCI USA David Crisp JPL USA John Hoessel UNIV. OF WISCONSIN USA Jay Gallagher UNIV. OF WISCONSIN USA Richard Griffiths JOHNS HOPKINS UNIV USA Jeff Hester ARIZONA STATE UNIV. USA John Holtzman LOWELL OBSERVATORY USA Jeremy Mould CALTECH USA James Westphal CALTECH USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. The proposed observations are images of both Io and its immediate vicinity in the emission lines of NaI, [SII], [SIII], [OI], and [OII], which extend groundbased investigations of the origin, maintenance, and variations in the observed structures. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. This subject has been investigated with increasingly sensitive techniques from the ground over the past decade. Spacecraft encounters with Jupiter, including Voyager and Ulysses, provide in situ `ground truth' for the proposed obervations by simultaneously sampling at close range the charged particle composition, radio emissions, and large aperture FUV spectra. These spacecraft encounters, by their nature, cannot distinguish radial from longitudinal structure in the torus, and provide data for only a few widely separated points in time. Galileo will dwell in the vicinity of Jupiter for over a year, but following orbital insertion it will avoid further passage through the plasma torus. The torus emissions observed from the earth in the visible are too faint for observation by cameras in any of the spacecraft mentioned above. The torus consistently displays important spatial structure at spatial scales smaller than can be resolved from the ground. HST provides the increase in spatial resolution required to probe spatial scales smaller than Io, which is needed to define and distinguish the plasma injection and loss mechanisms. The proposed images contain both the torus line emissions and continuum background scattered and diffracted from Jupiter and its satellites. Required exposure times for atomic emissions are known from groundbased experience. With Io in the field of view, its surface brightness becomes the major factor in choosing exposure times. Exposure times are bracketed by the effects of surface-reflected continuum at the short end and need for S/N in atomic emissions at the long end. Page 3 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Electron-exicted emissions from the torus are faint compared to reflected continuum from both Jupiter and its Galilean satellites, even as seen in narrowband filters. Visibility of the Io/torus interaction region therefore depends on the orbital phases of Io as well as the the other Galilean satellites. For one set of observations, we wish to observe Io in eclipse but as far as possible from the bright Jovian disk. The HST should be rolled to place the Jovian rotational axis approximately parallel (within 10 degrees) to the columns in the selected CCD camera, in order to minimize the effects of diffraction spikes and blooming. ------------------------------------------------------------------------------------ 11. Address Information Name: JOHN T. TRAUGER Category: PI Institution: 2370 Address: 4800 OAK GROVE DRIVE MAIL STOP 179-225 City: PASADENA State: CA Zip Code: 91109 Country: USA Telephone: 818-354-9594 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5218 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: IO-TORUS-WEST ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 240 300, | OLG OF JUPITER BETWEEN 310 50, | SEP OF EUROPA IO FROM EARTH GT 17", | SEP OF GANYMEDE IO FROM EARTH GT 17", | SEP OF CALLISTO IO FROM EARTH GT 17" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |V = 5.2 +/- 0.5 | EMPHASIS ON IO TRAILING HEMISPHERE 2 |SIZE = 1.11 +/- 0.07 | FOR SEQUENCES IN CYCLE 4. | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5218 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 10.0 S 100 1 # CORONA1 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 1.2 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F502N ATD-GAIN=15 1 40.0 S 100 1 # CORONA1 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 1.3 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 200.0 S 100 1 # CORONA1 WEST CR-SPLIT=NO CLOCKS=YES Comments: LONG EXPOSURE, IO WILL BLOOM ------------------------------------------------------------------------------------------------------------------------------------ 2.1 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 10.0 S 100 1 # CORONA2 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 2.2 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F673N ATD-GAIN=15 1 10.0 S 100 1 # CORONA2 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 2.3 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F673N ATD-GAIN=15 1 200.0 S 100 1 # CORONA2 WEST CR-SPLIT=NO CLOCKS=YES Comments: LONG EXPOSURE, IO WILL BLOOM ------------------------------------------------------------------------------------------------------------------------------------ 3.1 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 10.0 S 100 1 # CORONA3 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 3.2 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F673N ATD-GAIN=15 1 10.0 S 100 1 # CORONA3 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 3.3 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F953N ATD-GAIN=15 1 140.0 S 100 1 # CORONA3 WEST CR-SPLIT=NO CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ 4.1 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 10.0 S 100 1 # CORONA4 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 4.2 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15 1 16.0 S 100 1 # CORONA4 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 4.3 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F631N ATD-GAIN=15 1 200.0 S 100 1 # CORONA4 WEST CR-SPLIT=NO CLOCKS=YES Comments: LONG EXPOSURE, IO WILL BLOOM ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5218 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 5.1 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F588N ATD-GAIN=15 1 10.0 S 100 1 # CORONA5 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 5.2 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F375N ATD-GAIN=7 1 600.0 S 100 1 # CORONA5 WEST CR-SPLIT=NO CLOCKS=NO ------------------------------------------------------------------------------------------------------------------------------------ 5.3 DEFINE IO-TORUS- WFPC2 IMAGE PC1-FIX F673N ATD-GAIN=15 1 200.0 S 100 1 # CORONA5 WEST CR-SPLIT=NO CLOCKS=YES Comments: LONG EXPOSURE, IO WILL BLOOM ------------------------------------------------------------------------------------------------------------------------------------ 11 USE 1 SEQ 1.1,1.2,1.3 NO CORONA1 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. ORIENT PC1 COLUMNS PARALLEL TO JOVIAN N-S AXIS, PA OF NORTH POLE IS +19 D AT OPPOSITION, POINT +U3 TO 19 - 45 D. INVESTIGATING NAI. ------------------------------------------------------------------------------------------------------------------------------------ 12 USE 1 SEQ 2.1,2.2.2.3 NO CORONA2 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [SII]. ------------------------------------------------------------------------------------------------------------------------------------ 13 USE 1 SEQ 3.1,3.2,3.3 NO CORONA3 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [SIII]. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5218 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 14 USE 1 SEQ 4.1,4.2,4.3 NO CORONA4 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [OI]. ------------------------------------------------------------------------------------------------------------------------------------ 15 USE 1 SEQ 5.1,5.2,5.3 NO CORONA5 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [OII] AND [SIII]. ------------------------------------------------------------------------------------------------------------------------------------ 16 USE 1 SEQ 1.1,1.2,1.3 NO CORONA1 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. ORIENT PC1 COLUMNS PARALLEL TO JOVIAN N-S AXIS, PA OF NORTH POLE IS +19 D AT OPPOSITION, POINT +U3 TO 19 - 45 D. INVESTIGATING NAI. ------------------------------------------------------------------------------------------------------------------------------------ 17 USE 1 SEQ 2.1,2.2.2.3 NO CORONA2 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [SII]. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5218 [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 18 USE 1 SEQ 1.1,1.2,1.3 NO CORONA1 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. ORIENT PC1 COLUMNS PARALLEL TO JOVIAN N-S AXIS, PA OF NORTH POLE IS +19 D AT OPPOSITION, POINT +U3 TO 19 - 45 D. INVESTIGATING NAI. ------------------------------------------------------------------------------------------------------------------------------------ 19 USE 1 SEQ 2.1,2.2.2.3 NO CORONA2 GAP ORIENT 334D +/- 10D PCS MODE F CYCLE 4 Comments: ORIENTATION REQUIRED TO CONTROL SCATTERED LIGHT AND BLOOMING. INVESTIGATING [SII]. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5218 [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN CR-SPLIT CLOCKS ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/WF2 ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 2.60 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category SATELLITES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1.1,1.2,1.3 NO GAP; ORIENT 334D +/- 10D; PCS MODE F; CYCLE 4 SEQ 2.1,2.2.2.3 NO GAP; SEQ 3.1,3.2,3.3 NO GAP; SEQ 4.1,4.2,4.3 NO GAP; SEQ 5.1,5.2,5.3 NO GAP; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F588N F502N F673N F953N F631N F375N ------------------------------------------------------------------------------------------------------------------------------------ Target Names IO-TORUS-WEST ------------------------------------------------------------------------------------------------------------------------------------