Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4601c Report Date: 09-May-96:19:44 Version: ********** Check-in Date: ********** 1.Proposal Title: JUPITER'S H LY ALPHA AURORAL/AIRGLOW LINE PROFILE: CYCLE 3 MEDIUM ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category GIANT PLANETS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone John T. Clarke UNIVERSITY OF MICHIGAN USA 313-747-3540 ------------------------------------------------------------------------------------ 7. Abstract In a series of IUE observations with 0.14 Angstrom resolution we have resolved the width of the H Ly alpha emission line from Jupiter's aurora and dayglow. The initial motivation was to detect the signature of proton aurora in Jupiter's hydrogen atmosphere, i.e. highly Doppler- shifted Ly alpha emission from fast proton charge exchange. No proton aurora have been observed on Jupiter, with a tight upper limit, but the auroral Ly alpha line does appear broadened with an asymmetry toward the blue (upward moving) side. Although this was initially interpreted in terms of fast protons accelerated by auroral potentials, it is also possible that it represents a supersonic thermospheric wind. Equatorial data on Jupiter have shown that the observed brightening, or "bulge", is due to a symmetric broadening of the line rather than a bright core (as expected for electron collisional excitation). This appears more consistent with a superthermal population in the upper atmosphere than particle excitation, and suggests that the auroral broadening may be a related process. We can in principle identify an auroral thermospheric expansion away from the auroral oval by spatially resolved spectra at points on either side of the auroral oval, and we propose to do this in cycle 3. We will then relate the auroral observations to scheduled equatorial observations in cycle 2. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 7.40 par: 0 10. Num targs pri: 6 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4601c PI: John T. Clarke Proposal Title: JUPITER'S H LY ALPHA AURORAL/AIRGLOW LINE PROFILE: CYCLE 3 MEDIUM ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi John T. Clarke 2660 USA Lotfi Ben Jaffel 5466 FRANCE X Randall Gladstone 1506 USA Renee Prange 5436 FRANCE X Alfred Vidal-Madjar 5466 FRANCE X Hunter Waite 3440 USA ------------------------------------------------------------------------------------ 2. Scientific Justification. ------------------------------------------------------------------------------------ 3. Description of proposed observations. We request 6 dark orbits for this program, with 5 orbits for 5 latitudes across the northern auroral oval on the central meridian and 1 orbit for sky background. Each dark orbit will include the observation of a specific latitude in Jupiter's northern auroral zone. All observations will be with GHRS G160M and the large aperture (LSA) for high spectral resolution and sensitivity. Pointing on Jupiter will be by blind offset, if this turns out to be accurate to a few tenths of an arc sec, otherwise we will peak up on one of the Galilean satellites and offset from there to the desired location on Jupiter. All observations may be performed with coarse track. The one orbit for a sky background measurement can be used for sky subtraction from all Jupiter spectra if the observations are scheduled close in time, and the observations should be scheduled near Jupiter opposition to minimize the geocoronal background. Scheduling restrictions will force these spectra to be taken over a period of several days, and we will therefore obtain a time-averaged view of the aurora. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The atomic hydrogen line emission from Jupiter's aurora can only be observed in the far-UV. Ground-based observations have now revealed quadrupole emissions of H2 and thermal emissions of H3+, but these emission line shapes are not diagnostic of the dynamics of the upper atmosphere. We hope to learn about the dynamics of Jupiter's auroral atmosphere, specifically the very large energy input to the upper atmosphere and possibly also the interaction between Jupiter's magnetosphere and auroral upper atmosphere. The 5 latitudes observed will be +40, +50, +55, +60, and +70 degrees. These are chosen to be centered on the torus auroral zone with an extension well north and south of this. Between longitudes of 150-200 degrees we will cover both sides of the expected auroral oval. The 5 latitudes are needed to properly sample any variations with latitude. Using the GHRS G160M with LSA at 1216 A, we expect .096 counts/sec- diode-kR for diffuse emission compared with a background rate of .008 counts/sec- diode. The auroral emission is in the range 10-100 kR in brightness, depending on the level of auroral activity and extent of the emitting region, and the planetary airglow is ~10 kR. For a 10 kR brightness and a line 0.2 Angstroms full width at half maximum (FWHM), we would have ~ 2000 counts/diode on the central part of the line in a 40 min. integration, or a S/N = 40. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. We desire to minimize the sky background subtraction, which involves minimizing the geocoronal background Ly alpha emission by observing Jupiter near opposition. All Jupiter spectra will also be taken when the north auroral zone is tilted toward the Earth, i.e. when the central meridian longitude is 150-200 degrees. Page 3 ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. The only specific calibrations for this program that are not generally available will be a flat field at the same y-deflection as the observations, and an LSA G160M scattered light and line profile measurement using the on-board Pt-Ne calibration lamps. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. The GHRS data will be reduced using standard programs obtained from the ST ScI and GHRS team at the University of Michigan. The analysis of the data will involve shifting and co-adding the individual FP-split segments, applying any flat field, and measuring and subtracting the background geocoronal and IPM emissions. The IPM emissions will be largely Doppler-shifted off the planetary lines. We will then compare models for the line profiles convolved with the GHRS point spread function with the data from each planet: R. Gladstone and L. Ben Jaffel will take the lead in modeling the data, and both have modeling codes ready for use. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. None. ------------------------------------------------------------------------------------ 9. Description of previous HST work. 1. GO 2602 - "The Excitation of the Atmospheres of Planetary Satellites", J. Clarke PI - unrelated. 2. GO 2603 - "Parallel Observations of H Ly alpha Emission from the Local ISM", J. Clarke PI - related for sky background. 3. GO 2393 - "D/H Ratio of Venus and Mars from Lyman alpha Emission", J. Clarke Co-I - unrelated. 4. GO 2625 - "Excitation Processes for the Outer Planet UV Emissions", J. Clarke Co-I - possibly related scientifically. 5. GO 3511 - "H Ly alpha Dayglow Emission Line Profiles from the Outer Planets", J. Clarke PI - related. 6. GO 3616 - "Upper Atmospheres of Uranus and Neptune", J. Clarke Co-I - may be related scientifically. 7. GO 3862 - "The Excitation of the Atmospheres of Planetary Satellites", J. Clarke PI - unrelated. 8. GTO 1269 - "Far UV Observations of the Giant Planets", A. Vidal-Madjar Co- I - related. 9. GO 2461 - "Interplanetary/interstellar gas connection: search for the local cloud" - A. Vidal-Madjar Co-I - unrelated. 10. GO 2536 - "Deuterium in the local interstellar gas" - A. Vidal-Madjar PI - unrelated. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Complete computing facilities are in place and available within the Space Physics Research Laboratory at the University of Michigan for use on this project. Two VAX 750's and a VAX 8600 are accessible via a local area network, in addition to the Michigan network MERIT, SPAN, and NASA Internet. Two Sun Sparcstations with IDL are presently being used for IUE and HST data reductions. All Co-Investigators also have complete computer facilities available at their institutions for use on this project, and graduate students are available at all institutions for assistance with this project. ------------------------------------------------------------------------------------ 11. Address Information Name: JOHN T. CLARKE Category: PI Institution: UNIVERSITY OF MICHIGAN Address: AOSS DEPT. City: ANN ARBOR State: MI Zip Code: 481092143 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4601c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: JUPITER+40 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: FEATURE JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 2. | TYPE=TORUS,POLE_LAT=90, | RAD=69370.,LAT=+40,LONG=0 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30, | CML OF JUPITER FROM EARTH | BETWEEN 150 200 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 | GHRS LSA WITH G160M ON JUPITER CML 2 |SURF-LINE(1216) = 2. +/- 1. E-11 | AND +40 DEGREES LATITUDE. OBSERVE H 3 |W-LINE(1216) = 0.15 +/- 0.1 | LY ALPHA LINE PROFILE FROM NEAR- | | AURORAL ATMOSPHERE WHEN LIII = 150- | | 200 DEG. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: JUPITER+50 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: FEATURE JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 2. | TYPE=TORUS,POLE_LAT=90, | RAD=68570.,LAT=+50,LONG=0 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30, | CML OF JUPITER FROM EARTH | BETWEEN 150 200 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 | GHRS LSA WITH G160M ON JUPITER CML 2 |SURF-LINE(1216) = 2. +/- 1. E-11 | AND +50 DEGREES LATITUDE. OBSERVE H 3 |W-LINE(1216) = 0.15 +/- 0.1 | LY ALPHA LINE PROFILE FROM NEAR- | | AURORAL ATMOSPHERE WHEN LIII = 150- | | 200 DEG. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4601c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: JUPITER+55 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: FEATURE JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 2. | TYPE=TORUS,POLE_LAT=90, | RAD=68190.,LAT=+55,LONG=0 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30, | CML OF JUPITER FROM EARTH | BETWEEN 150 200 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 | GHRS LSA WITH G160M ON JUPITER CML 2 |SURF-LINE(1216) = 2. +/- 1. E-11 | AND +55 DEGREES LATITUDE. OBSERVE H 3 |W-LINE(1216) = 0.15 +/- 0.1 | LY ALPHA LINE PROFILE FROM NEAR- | | AURORAL ATMOSPHERE WHEN LIII = 150- | | 200 DEG. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: JUPITER+60 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: FEATURE JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 2. | TYPE=TORUS,POLE_LAT=90, | RAD=67840.,LAT=+60,LONG=0 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30, | CML OF JUPITER FROM EARTH | BETWEEN 150 200 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 | GHRS LSA WITH G160M ON JUPITER CML 2 |SURF-LINE(1216) = 2. +/- 1. E-11 | AND +60 DEGREES LATITUDE. OBSERVE H 3 |W-LINE(1216) = 0.15 +/- 0.1 | LY ALPHA LINE PROFILE FROM NEAR- | | AURORAL ATMOSPHERE WHEN LIII = 150- | | 200 DEG. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4601c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 | TARGET NAME: JUPITER+70 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: FEATURE JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 2. | TYPE=TORUS,POLE_LAT=90, | RAD=67270.,LAT=+70,LONG=0 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30, | CML OF JUPITER FROM EARTH | BETWEEN 150 200 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 | GHRS LSA WITH G160M ON JUPITER CML 2 |SURF-LINE(1216) = 2. +/- 1. E-11 | AND +70 DEGREES LATITUDE. OBSERVE H 3 |W-LINE(1216) = 0.15 +/- 0.1 | LY ALPHA LINE PROFILE FROM NEAR- | | AURORAL ATMOSPHERE WHEN LIII = 150- | | 200 DEG. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 6 | TARGET NAME: SKY-BACKGROUND ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER, ACQ = 30. | TYPE=POS_ANGLE,RAD=180., | ANG=0.,REF=NORTH | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN -30 30 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF-LINE(1216) = 1. +/- 1. E-11 | GHRS LSA WITH G160M ON SKY ROUGHLY 3 2 |W-LINE(1216) = 0.10 +/- 0.1 | ARC MIN FROM JUPITER. OBSERVE H LY | | ALPHA LINE PROFILE FROM SKY | | BACKGROUND GEO AND IPM EMISSIONS. | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4601c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 JUPITER+40 HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 CYCLE 3 / 1-6 STEP-PATT=DEF PCS MODE C / 1-6 STEP-TIME=1.0 DARK TIME /1-6 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ 2 JUPITER+50 HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 STEP-PATT=DEF STEP-TIME=1.0 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ 3 JUPITER+55 HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 STEP-PATT=DEF STEP-TIME=1.0 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ 4 JUPITER+60 HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 STEP-PATT=DEF STEP-TIME=1.0 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ 5 JUPITER+70 HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 STEP-PATT=DEF STEP-TIME=1.0 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ 6 SKY- HRS ACCUM 2.0 G160M 1223.0 FP-SPLIT=STD 4 660S 2 1 BACKGROUND STEP-PATT=DEF STEP-TIME=1.0 DOPPLER=ON ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4601c [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FP-SPLIT STEP-PATT STEP-TIME=1.0 DOPPLER ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 7.40 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category GIANT PLANETS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 3 / 1-6; PCS MODE C / 1-6; DARK TIME /1-6; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names JUPITER+40 JUPITER+50 JUPITER+55 JUPITER+60 JUPITER+70 SKY-BACKGROUND ------------------------------------------------------------------------------------------------------------------------------------