6662( 10) - 07/02/97 15:38 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6662 Version: 10 Check-in Date: 02-Jul-1997 15:38:00 1.Proposal Title: Observation of short timescale variability of the Jovian UV aurora ------------------------------------------------------------------------------------ 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 (Belgium) N CoI: Denis Grodent Universite de Liege (Belgium) Y CoI: Gilda Ballester University of Michigan (USA/MI) N CoI: John Clarke University of Michigan (USA/MI) N CoI: John T. Trauger Jet Propulsion Laboratory (USA/CA) N ------------------------------------------------------------------------------------ 6. Abstract Previous FOC and WFPC2 observations have shown the very complex morphological structure of the Jovian UV aurora and its unexpectedly strong temporal variations. They (and other IUE and Voyager UVS observations) suggest that time variations occur on different timescales. Some of the auroral structures deduced from previous images may be the result of a time averaging of short-lived auroral features. We propose to image the short time variations (minutes) of the ultraviolet Jovian auroral morphology and brightness with WFPC2. Exposures will be made near central meridian longitudes (CMLs) = 180 degrees in order to get the best view of the northern auroral zone. The question of temporal variability is of major importance in understanding the origin and acceleration mechanisms of the auroral particles exciting the Jovian UV aurora. ------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 2] Observations Description ------------------------ We propose to image the short timescale variability of the Jovian polar regions with WFPC2. Two visits of one orbit each covering CMLs around 180 degrees (lambda III) will be selected to give the best viewing geometry of the auroral region and to obtain statistically significant results. During the first visit, the PC1 chip will take : - 1 short exposure (4s) of the visible disk of Jupiter through the F673N filter in order to obtain a sharp limb determination. - 6 consecutive UV exposures of the auroral emission (200s) through the F160BW Wood's filter. This filter has proven to be perfectly suited to auroral observation as it provides good contrast between the UV emission (H2 Lyman and Werner bands) and the bright disk background. Analyses of previous WFPC2 auroral images show that a 100s exposure time is a good compromise between the pixel count rate and the signal dilution due to the planet's rotation. During the second visit, the WF3 chip will take : - 1 short exposure (1s) of the visible disk of Jupiter through the F673N filter in order to obtain a sharp limb determination. - 8 consecutive UV exposures of the auroral emission (160s) through the F160BN15 Wood's filter. The second visit will occur one Jovian rotation (~ 10 hours) after the beginning of the first visit in order to cover timescale variations ranging from minutes to hours, and to obtain images with comparable CMLs from one visit to the other. The program must be carried out near quadrature in order to include the complete Jovian disk in the PC1 field. Real Time Justification ----------------------- The observations must be carried out (between 05 May 1997 and May 28 1997) or (between June 30 1997 and July 20 1997) Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 3] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: JUPITER-AURORA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET JUPITER ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | TYPE=TORUS,LONG=0,LAT=+30,RAD=66770,POLE | _LAT=+90 | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | CML OF JUPITER FROM EARTH BETWEEN 155 | 215, OLG OF IO BETWEEN 110 250 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | SURF(V) = 5.3+/-0.05 | Jovian CMLs are expressed in System- U-B = 0.48 | III longitude. B-V = 0.83 | | ------------------------------------------------------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 4] Visit: 01 Visit Requirements: PCS MODE F BETWEEN 05-MAY-97 AND 28-MAY-97 BETWEEN 30-JUN-97 AND 20-JUL-97 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUPITER-AUR WFPC2 IMAGE PC1-FIX F673N ATD-GAIN = 7 1 4 S SEQ 1-2 NON-INT ORA ------------------------------------------------------------------------------------------------------------------------------------ 2 JUPITER-AUR WFPC2 IMAGE PC1-FIX F160BW ATD-GAIN = 7 6 200 S ORA ------------------------------------------------------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 5] Visit: 51 Visit Requirements: PCS MODE F BETWEEN 28-JUL-97 and 11-aug-97 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUPITER-AUR WFPC2 IMAGE WF3 F673N ATD-GAIN = 7 1 1 S SEQ 1-2 NON-INT ORA ------------------------------------------------------------------------------------------------------------------------------------ 2 JUPITER-AUR WFPC2 IMAGE WF3 F160BN15 ATD-GAIN = 7 8 160 S ORA ------------------------------------------------------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 6] Visit: 02 Visit Requirements: PCS MODE F On Hold Comments: Additional Comments: To be done at quadrature. Visit #2 must start 1 Jovian rotation (~10H) after the beginning of visit #1, the viewing geometry of both visits will therefore be comparable (same CMLs). Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUPITER-AUR WFPC2 IMAGE WF3 F673N ATD-GAIN = 7 1 1 S SEQ 1-2 NON-INT ORA ------------------------------------------------------------------------------------------------------------------------------------ 2 JUPITER-AUR WFPC2 IMAGE WF3 F160BN15 ATD-GAIN = 7 8 160 S ORA ------------------------------------------------------------------------------------------------------------------------------------ 6662( 10) - 07/02/97 15:38 - [ 7] Summary Form for Proposal 6662 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN = 7 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F BETWEEN 05-MAY-97 AND 28-MAY-97 BETWEEN 30-JUN-97 AND 20-JUL-97 SEQ 1-2 NON-INT PCS MODE F BETWEEN 28-JUL-97 and 11-aug-97 PCS MODE F ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F673N F160BW F160BN15 ------------------------------------------------------------------------------------------------------------------------------------ Target Names JUPITER-AURORA ------------------------------------------------------------------------------------------------------------------------------------