6648( 10) - 08/25/97 10:50 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6648 Version: 10 Check-in Date: 25-Aug-1997 10:48:41 1.Proposal Title: The link between the UV Saturnian aurora and the polar stratospheric haze ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle SOLAR SYSTEM GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: JEAN CLAUDE M.C. GERARD UNIVERSITE DE LIEGE CoI: Vincent Dols Universite de Liege Y CoI: Denis Grodent Universite de Liege N CoI: G. Randall Gladstone Southwest Research Institute N CoI: Laurence Trafton McDonald Observatory N CoI: J. Hunter Waite Southwest Research Institute N ------------------------------------------------------------------------------------ 6. Abstract We propose to image the Saturn ultraviolet aurora and dark polar caps for a detailed investigation of the morphology of Saturn's aurora near both poles and a study of its relationship with the stratospheric polar haze possibly generated by auroral ionization. The purpose of these observations is manyfold : (1) To study the latitudinal, longitudinal and temporal variation of the aurora of both hemispheres. This result may be achieved by imaging a full planetary rotation using the UV sensitive Wood's filters of the WFPC2 camera. (2) To image polar caps in wavelengths without auroral contamination to obtain a multispectral high resolution mapping of the polar haze opacity and scattering properties ------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 2] Observations Description ------------------------ We propose to first obtain a series of exposures of Saturn's disk with WFPC2 using the PC chip. Its field of view is wide enough to include both polar regions near opposition (where Saturn's apparent diameter is ~ 19 arcsec). For auroral and haze imaging, we plan to cover a full Saturnian rotation to image all planetary longitudes (8 HST orbits). In this way, we will determine if the auroral morphology and brightness exhibit a true longitudinal variation, fixed in SIII coordinates, as the Jovian aurora or is linked to local time as in the case of the Earth's aurora. The F160BW Wood's filter is ideally suited for the auroral mapping as it includes most of the H_2 Lyman and Werner bands and Ly- Alpha. This filter has a high red leak rejection and provides good contrast against the background sunlit planetary disk. Based on the typical peak brightness of ~ 150 kR previously observed with the FOC on Saturn's aurora on past experience with WFPC2 images of Jupiter's UV aurora, (Clarke J.T., et al., Science, 1995, 267, 1302) exposures ~ 1000s will provide a good compromise between auroral temporal variation, S/N ratio, smearing of the planetary rotation and cosmic noise background. Since temporal variations on the time scale of tens of minutes are expected, we take two consecutive 1000s exposures (no CR-SPLIT) with the same filter on alternate (odd numbered) HST orbits. If the aurora is steady over the ~ 50 min time span of Saturn visibility, the exposures will be co-added after suitable longitudinal shift. The two auroral F160BW exposures will be followed by a 10s exposure of the disk in the methane filter at 8929 Angstrom (FQCH4P15). This image will provide the accurate location of the planetary disk which is necessary for the detailed mapping of the aurora. Previous experience with the WFPC2 images obtained during the SL/9- Jupiter encounter has indicated that a WFPC2 1-pixel precision on the limb position may be obtained. This image will also be used to examine the polar haze morphology as it is known from Jupiter studies that high-altitude aerosols, because of their efficient scattering, are contrasted extremely well in the 8900 Angstrom \\ methane band. , Even-numbered HST orbits will also start with a 1000s auroral image with the F160BW filter. A subsequent F160BW + F165LP 1500s exposure (no CR-SPLIT) will be made to separate the light reflected by the disk and absorbed by the polar hood aerosols from the auroral contribution. In this way, it will be possible to closely examine the morphology of the UV aerosols (without auroral contaminations) and compare the results with the methane band images which are sensitive to the same particles but at somewhat lower altitudes. , Finally, during the 9th orbit 1000s haze images with the F255W and F218W filters will be made. It will be useful as a calibration check of the F160BW + F165LP haze images since their stability and photometric responses are better characterized than that of the Wood's filter. In addition, the spectral response of F218W is quite similar to that of the F210M + F220W FOC filters used for previous studies. Real Time Justification ----------------------- The observations should ideally be carried out near opposition. none Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: SATURN-150 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET SATURN ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=SATURN | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF SATURN FROM EARTH BETWEEN 300 60, | CML OF SATURN FROM EARTH BETWEEN 100 200 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | B-V = 1.04 | SATURN AT OPPOSITION +/- 60 D CML U-B = 0.58 | expressed in System-III coordinates SURF(V) = 6.7+/-0.2 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: SATURN-UV ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET SATURN ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=SATURN | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF SATURN FROM EARTH BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | B-V = 1.04 | SATURN AT OPPOSITION +/- 60 D U-B = 0.58 | SURF(V) = 6.7+/-0.2 | | ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 5] Visit: 01 Visit Requirements: PCS MODE F On Hold Comments: Additional Comments: this visit should cover 8 consecutive orbits, targets should be positioned at the same location in the PC1 FOV for each exposure of the visit Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 SATURN-150 WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 800 S SEQ 11-13 NON-INT POS 5 TARG -0.885,-5.096 Comments: EXPOSURES 11-13 on the same unocculted orbit CML OF SATURN AT THE BEGINNING OF FIRST EXPOSURE AS CLOSE TO 150D (S_III) AS POSSIBLE ------------------------------------------------------------------------------------------------------------------------------------ 12 SATURN-150 WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 800 S SAME POS AS 11 5 ------------------------------------------------------------------------------------------------------------------------------------ 13 SATURN-150 WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 80 S SAME POS AS 11 5 Comments: This exposure will be used to determine the limb for the exposures 11-12 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 21 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 1000 S POS TARG -0.885,-5.096 5 SEQ 21-22 NON-INT Comments: EXPOSURES 21-22 on the same unocculted orbit immediately following the 11-13 orbit ------------------------------------------------------------------------------------------------------------------------------------ 22 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW, CR-SPLIT=NO 1 1200 S SAME POS AS 21 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 31 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 800 S POS TARG -0.885,-5.096 5 SEQ 31-33 NON-INT Comments: EXPOSURES 31-33 on the same unocculted orbit immediately following the 21-22 orbit ------------------------------------------------------------------------------------------------------------------------------------ 32 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 900 S SAME POS AS 31 5 ------------------------------------------------------------------------------------------------------------------------------------ 33 SATURN-UV WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 100 S SAME POS AS 31 5 Comments: This exposure will be used to determine the limb for the exposures 31-32 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 41 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 1000 S POS TARG -0.885,-5.096 5 SEQuence 41-42 NON-INT Comments: EXPOSURES 41-42 on the same unocculted orbit immediately following the 31-33 orbit ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 42 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW, CR-SPLIT=NO 1 1200 S SAME POS AS 41 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 51 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 1000 S POS TARG -0.885,-5.096 5 SEQ 51-53 NON-INT Comments: EXPOSURES 51-53 on the same unocculted orbit immediately following the 41-42 orbit ------------------------------------------------------------------------------------------------------------------------------------ 52 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 900 S SAME POS AS 51 5 ------------------------------------------------------------------------------------------------------------------------------------ 53 SATURN-UV WFPC2 IMAGE FQCH4P1 F673N 1 10 S SAME POS AS 51 5 Comments: This exposure will be used to determine the limb for the exposures 51-52 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 61 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 1000 S SEQ 61-62 NON-INT POS 5 TARG -0.885,-5.096 Comments: EXPOSURES 61-62 on the same unocculted orbit immediately following the 51-53 orbit ------------------------------------------------------------------------------------------------------------------------------------ 62 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW, CR-SPLIT=NO 1 1200 S SAME POS AS 61 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 71 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 1000 S SEQ 71-72 NON-INT POS 5 TARG -0.885,-5.096 Comments: EXPOSURES 71-72 on the same unocculted orbit immediately following the 61-62 orbit ------------------------------------------------------------------------------------------------------------------------------------ 72 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW, CR-SPLIT=NO 1 1200 S SAME POS AS 71 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 81 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 800 S SEQ 81-83 NON-INT POS 5 TARG -0.885,-5.096 Comments: EXPOSURES 81-83 on the same unocculted orbit immediately following the 71-72 orbit ------------------------------------------------------------------------------------------------------------------------------------ 82 SATURN-UV WFPC2 IMAGE FQCH4P1 F160BW CR-SPLIT=NO 1 900 S SAME POS AS 81 5 ------------------------------------------------------------------------------------------------------------------------------------ 83 SATURN-UV WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 120 S SAME POS AS 81 5 Comments: This exposure will be used to determine the limb for the exposures 81-82 and thus need to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 7] Visit: 02 Visit Requirements: PCS MODE F AFTER 1 BY 720M TO 820M On Hold Comments: Additional Comments: this visit must be scheduled as close as possible to the first visit but outside the SAA contamination. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 90 SATURN-UV WFPC2 IMAGE FQCH4P1 F218W CR-SPLIT=NO 1 800 S SEQ 90-92 NON-INT POS 5 TARG -0.885,-5.096 Comments: EXPOSURES 90-92 in the same unocculted orbit ------------------------------------------------------------------------------------------------------------------------------------ 91 SATURN-UV WFPC2 IMAGE FQCH4P1 F218W CR-SPLIT=NO 1 700 S SAME POS AS 90 5 Comments: EXPOSURES 91 92 on the same unocculted orbit ------------------------------------------------------------------------------------------------------------------------------------ 92 SATURN-UV WFPC2 IMAGE FQCH4P1 F255W 1 300 S SAME POS AS 90 5 ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 8] Visit: 51 Visit Requirements: PCS MODE F On Hold Comments: Additional Comments: this visit should cover 8 consecutive orbits. All F160BW exposures place the target in the F160BN15 aperture, all others use the FQCH4P15 aperture. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 SATURN-150 WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 800 S SEQ 11-13 NON-INT 5 Comments: EXPOSURES 11-13 on the same unocculted orbit CML OF SATURN AT THE BEGINNING OF FIRST EXPOSURE AS CLOSE TO 150D (S_III) AS POSSIBLE ------------------------------------------------------------------------------------------------------------------------------------ 12 SATURN-150 WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 800 S 5 ------------------------------------------------------------------------------------------------------------------------------------ 13 SATURN-150 WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 80 S 5 Comments: This exposure will be used to determine the limb for the exposures 11-12 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 21 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 1000 S SEQ 21-22 NON-INT 5 Comments: EXPOSURES 21-22 on the same unocculted orbit immediately following the 11-13 orbit ------------------------------------------------------------------------------------------------------------------------------------ 22 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15, CR-SPLIT=NO 1 1200 S 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 31 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 800 S SEQ 31-33 NON-INT 5 Comments: EXPOSURES 31-33 on the same unocculted orbit immediately following the 21-22 orbit ------------------------------------------------------------------------------------------------------------------------------------ 32 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 900 S 5 ------------------------------------------------------------------------------------------------------------------------------------ 33 SATURN-UV WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 100 S 5 Comments: This exposure will be used to determine the limb for the exposures 31-32 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 41 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 1000 S SEQuence 41-42 NON-INT 5 Comments: EXPOSURES 41-42 on the same unocculted orbit immediately following the 31-33 orbit ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 9] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 42 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15, CR-SPLIT=NO 1 1200 S 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 51 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 990 S SEQ 51-53 NON-INT 5 Comments: EXPOSURES 51-53 on the same unocculted orbit immediately following the 41-42 orbit ------------------------------------------------------------------------------------------------------------------------------------ 52 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 900 S 5 ------------------------------------------------------------------------------------------------------------------------------------ 53 SATURN-UV WFPC2 IMAGE FQCH4P1 F673N 1 10 S 5 Comments: This exposure will be used to determine the limb for the exposures 51-52 and thus needs to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 61 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 1000 S SEQ 61-62 NON-INT 5 Comments: EXPOSURES 61-62 on the same unocculted orbit immediately following the 51-53 orbit ------------------------------------------------------------------------------------------------------------------------------------ 62 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15, CR-SPLIT=NO 1 1200 S 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 71 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 1000 S SEQ 71-72 NON-INT 5 Comments: EXPOSURES 71-72 on the same unocculted orbit immediately following the 61-62 orbit ------------------------------------------------------------------------------------------------------------------------------------ 72 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15, CR-SPLIT=NO 1 1200 S 5 F165LP ------------------------------------------------------------------------------------------------------------------------------------ 81 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 800 S SEQ 81-83 NON-INT 5 Comments: EXPOSURES 81-83 on the same unocculted orbit immediately following the 71-72 orbit ------------------------------------------------------------------------------------------------------------------------------------ 82 SATURN-UV WFPC2 IMAGE F160BN1 F160BN15 CR-SPLIT=NO 1 900 S 5 ------------------------------------------------------------------------------------------------------------------------------------ 83 SATURN-UV WFPC2 IMAGE FQCH4P1 FQCH4P15 8929 1 110 S 5 Comments: This exposure will be used to determine the limb for the exposures 81-82 and thus need to be exactly at the same location in the PC FOV ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 10] Visit: 52 Visit Requirements: PCS MODE F AFTER 1 BY 720M TO 820M On Hold Comments: Additional Comments: this visit must be scheduled as close as possible to the first visit but outside the SAA contamination. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 90 SATURN-UV WFPC2 IMAGE FQCH4P1 F218W CR-SPLIT=NO 1 800 S SEQ 90-92 NON-INT 5 Comments: EXPOSURES 90-92 in the same unocculted orbit ------------------------------------------------------------------------------------------------------------------------------------ 91 SATURN-UV WFPC2 IMAGE FQCH4P1 F218W CR-SPLIT=NO 1 700 S 5 Comments: EXPOSURES 91 92 on the same unocculted orbit ------------------------------------------------------------------------------------------------------------------------------------ 92 SATURN-UV WFPC2 IMAGE FQCH4P1 F255W 1 300 S 5 ------------------------------------------------------------------------------------------------------------------------------------ 6648( 10) - 08/25/97 10:50 - [ 11] Summary Form for Proposal 6648 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F SEQ 11-13 NON-INT POS TARG -0.885,-5.096 SAME POS AS 11 POS TARG -0.885,-5.096 SEQ 21-22 NON-INT SAME POS AS 21 POS TARG -0.885,-5.096 SEQ 31-33 NON-INT SAME POS AS 31 POS TARG -0.885,-5.096 SEQuence 41-42 NON-INT SAME POS AS 41 POS TARG -0.885,-5.096 SEQ 51-53 NON-INT SAME POS AS 51 SEQ 61-62 NON-INT POS TARG -0.885,-5.096 SAME POS AS 61 SEQ 71-72 NON-INT POS TARG -0.885,-5.096 SAME POS AS 71 SEQ 81-83 NON-INT POS TARG -0.885,-5.096 SAME POS AS 81 PCS MODE F AFTER 1 BY 720M TO 820M SEQ 90-92 NON-INT POS TARG -0.885,-5.096 SAME POS AS 90 SEQ 11-13 NON-INT SEQ 61-62 NON-INT SEQ 71-72 NON-INT SEQ 81-83 NON-INT SEQ 90-92 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160BW FQCH4P15 F160BW,F165LP F673N F218W F255W F160BN15 F160BN15,F165LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names SATURN-150 SATURN-UV ------------------------------------------------------------------------------------------------------------------------------------