6853( 10) - 08/18/97 17:47 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6853 Version: 10 Check-in Date: 18-Aug-1997 17:46:12 1.Proposal Title: Emission Features near Eclipsed Io ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Solar System GTO/WF2 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: John Trauger Jet Propulsion Laboratory CoI: Jon Holtzman Lowell Observatory N CoI: Jeremy Mould Mt. Stromlo and Siding Spring Observatory N CoI: James Westphal California Institute of Technology N CoI: John Clarke University of Michigan N CoI: Gilda Ballester University of Michigan N CoI: Karl Stapelfeldt Jet Propulsion Laboratory N CoI: Robin Evans Jet Propulsion Laboratory N CoI: Chris Burrows Space Telescope Science Institute N CoI: Dave Crisp Jet Propulsion Laboratory N CoI: John Hoessel University of Wisconsin N CoI: Jay Gallagher University of Wisconsin N CoI: Richard Griffiths Johns Hopkins University N CoI: Jeff Hester Arizona State University N ------------------------------------------------------------------------------------ 6. 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, ground based 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). ------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 2] Observations Description ------------------------ We wish to observe Io (visible PC images) in eclipse *just after ingress* into Jupiter's shadow, which requires that this program be scheduled in the early part of Cycle 6 to take advantage of Jupiter's 4 July 1996 opposition. There is about a 1 hour window between the time when Io enters Jupiter's shadow and when it becomes occulted by Jupiter's disk. To minimize scattered light, we wish to observe the eclipsed Io at the maximum angular separation from Jupiter. The scheduling trick will be to identify an HST orbit where 45 minutes of Io visibility coincide with the window during which Io is observable in shadow. There are lots of events to choose from, so this should be schedulable if the orbit we need is identified as soon as possible and then reserved for this program. Not all eclipses are equal, since the apparent separation of Io from Jupiter during ingress varies throughout the year. Larger separations are better, for they reduce scattered light from Jupiter and increase the duration of the event. These considerations drive us to prefer an eclipse within +/- 1 month of April 30 1996. Finally, a specific roll angle for HST is also requested to minimize the effects of diffraction spikes and blooming. We request two visits, separated by a week or more, to better understand the variability of the atomic species near Io, variations that arise largely in response to the plasma torus variability on time scales of a week or more. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 3] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: IO-ECLIPSE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, CML OF JUPITER | FROM IO BETWEEN 75 145, SEP OF JUPITER | IO FROM EARTH GT 8", SEP OF EUROPA IO | FROM EARTH GT 25", SEP OF GANYMEDE IO | FROM EARTH GT 25", SEP OF CALLISTO IO | FROM EARTH GT 25" | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 5.2+/-0.5 | IO IN ECLIPSE AND WELL SEPARATED SIZE=1.11+/-0.07 | FROM JUPITER. (POSSIBLE DATES AND | TIMES NOW EXIST IN AN EPHEMERIS | TABLE AT JPL.) | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: IO-ECLIPSE-NOCML ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, SEP OF JUPITER | IO FROM EARTH GT 8", SEP OF EUROPA IO | FROM EARTH GT 25", SEP OF GANYMEDE IO | FROM EARTH GT 25", SEP OF CALLISTO IO | FROM EARTH GT 25" | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 5.2+/-0.5 | IO IN ECLIPSE AND WELL SEPARATED SIZE=1.11+/-0.07 | FROM JUPITER. (POSSIBLE DATES AND | TIMES NOW EXIST IN AN EPHEMERIS | TABLE AT JPL.) | ------------------------------------------------------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: IO-ECL-EGRESS ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, SEP OF JUPITER | IO FROM EARTH GT 8", SEP OF EUROPA IO | FROM EARTH GT 25", SEP OF GANYMEDE IO | FROM EARTH GT 25", SEP OF CALLISTO IO | FROM EARTH GT 25" | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 5.2+/-0.5 | IO IN ECLIPSE AND WELL SEPARATED SIZE=1.11+/-0.07 | FROM JUPITER. (POSSIBLE DATES AND | TIMES NOW EXIST IN AN EPHEMERIS | TABLE AT JPL.) | ------------------------------------------------------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 5] Visit: 01 Visit Requirements: ORIENT 245D TO 275D PCS MODE F On Hold Comments: Additional Comments: Io in Eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F588N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 Comments: Unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 12 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F588N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 13 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 14 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 17 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F673N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 18 IO-ECLIPSE WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 Comments: Unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 6] Visit: 02 Visit Requirements: ORIENT 245D TO 275D; PCS MODE F On Hold Comments: Additional Comments: Io in Eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F588N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 NOCML Comments: Unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 22 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F588N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 NOCML Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 23 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 NOCML Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 24 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 NOCML Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 25 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 NOCML Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 27 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F673N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 NOCML Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 28 IO-ECLIPSE- WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 NOCML Comments: Unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 7] Visit: 03 Visit Requirements: SCHED 100%; ORIENT 61D TO 81D PCS MODE F On Hold Comments: Additional Comments: Io in Eclipse Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F673N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 SS Comments: Unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 32 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F673N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 SS Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 33 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 SS Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 34 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 SS Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 35 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F631N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 SS Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 36 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F588N CLOCKS=YES,CR-SPLIT=NO,ATD-GAIN=7 1 260 S POS TARG -12.0,-11.8 SS Comments: Eclipsed Io 6" from Pyramid apex ------------------------------------------------------------------------------------------------------------------------------------ 37 IO-ECL-EGRE WFPC2 IMAGE PC1-FIX F631N CR-SPLIT=NO,ATD-GAIN=7 1 0.50 S POS TARG -12.0,-11.8 SS Comments: Io now in sunlight, and unsaturated Jupiter in WF3 for reference ------------------------------------------------------------------------------------------------------------------------------------ 6853( 10) - 08/18/97 17:47 - [ 8] Summary Form for Proposal 6853 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ATD-GAIN=7 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GTO/WF2 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Solar System ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 245D TO 275D PCS MODE F POS TARG -12.0,-11.8 ORIENT 245D TO 275D; PCS MODE F SCHED 100%; ORIENT 61D TO 81D PCS MODE F ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F588N F631N F673N ------------------------------------------------------------------------------------------------------------------------------------ Target Names IO-ECLIPSE IO-ECLIPSE-NOCML IO-ECL-EGRESS ------------------------------------------------------------------------------------------------------------------------------------