7223( 10) - 02/25/98 15:44 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7223 Version: 10 Check-in Date: 25-Feb-1998 15:41:38 1.Proposal Title: Spectrophotometry and Imaging of Pluto and Charon ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GTO/NIC 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: RICH TERRILE JET PROPULSION LAB CoI: D. W. Koerner Jet Propulsion Laboratory N CoI: B. A. Smith University of Hawaii N CoI: R. Meier University of Hawaii N CoI: R. H. Brown University of Arizona N CoI: T. Owen University of Hawaii N CoI: G. Schneider University of Arizona N ------------------------------------------------------------------------------------ 5. Abstract Detailed spectra of the individual members of the Pluto-Charon system are not known. Different surface compositions are suggested by some evidence obtained when the two were undergoing mutual eclipses. Grism spectrophotometry will provide a direct comparison of the surface materials of each member of the double planet. Dispersion should be approximately normal to a line joining Pluto and Charon, and observations should be made in four separate orbital positions in order to differentiate surface variations on the two objects. Charon's leading (in Charon's orbital direction), trailing, Pluto-facing and non-Pluto-facing hemispheres will be observed. ------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 2] Observations Description ------------------------ These observations make use of near-IR Grism spectroscopy at high spatial resolution (NICMOS3) to obtain separate spectral signatures for Pluto and its moon, Charon. It is critical that the field orientation correspond to an alignment of the grisms with the dispersion direction normal to an imaginary line between the sky-positions of Pluto and Charon, since they have a very small angular separation, in the range 1.3 to 3.3 pixels. The Position Angle of this line (PA ~ 175 or 355 at elongation => PA_dispersion ~ 85 or 265, and PA ~ 265 or 85 at orbital longitudes that are 90 degrees away => PA_dispersion ~ 175 or 355,) should not change significantly throughout the course of Cycle 7, so this requirement can be met by the orient specifications given below. Four visits are outlined for Cycle 7; two should be timed within Charon's 6.5 day orbit such that Charon is at alternate elongations, and two when Charon is at its smallest angular separation. This requirement is satisfied by specifying a narrow window for in Charon's Orbital Longitude. We find that only the orientation corresponding to observations of Charon's hemispheres facing and looking away from Pluto are schedulable within the coming January campaign. Therefore we have placed the other two orbits on hold for observations during anticipated later campaigns. The positioning of the array is intended to allow detection of the first and second spectral orders and dithering for background subtraction at the longest wavelength. Cameras 1 and 2 are turned on simultaneously to eliminate the interference pattern which otherwise introduces a striping pattern in the images. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Rodger Thompson*Steward Observatory*University of Arizona*Tucson, AZ 85721 Ship Via: Email: thompson@as.arizona.edu ------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 3] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: CHARON-OLG360 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | STD=CHARON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON BETWEEN 345 15 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 14.9 | B-V = 1.2 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: CHARON-OLG180 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | STD=CHARON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON BETWEEN 165 195 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 14.9 | B-V = 1.2 | | ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: CHARON-OLG270 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | STD=CHARON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON BETWEEN 255 285 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 14.9 | B-V = 1.2 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: CHARON-OLG90 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | STD=CHARON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON BETWEEN 75 105 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 14.9 | B-V = 1.2 | | ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 5] Visit: 01 Visit Priority: Visit Requirements: SCHED 70% ORIENT 280D TO 310D On Hold Comments: Additional Comments: This visit is to capture emission from the hemisphere of Charon facing away from Pluto -- to do this, Charon is scheduled at approximately OLG = 0. At this time, the PA of a line between Pluto and Charon is at approximately 85 degrees. We want the Y axis along this PA so that the dispersion direction (perpendicular to Y) is perpendicular to the line between Pluto and Charon, yielding the least possible overlap in the spectra. Since the HST ORIENT specified is ORIENT = PA-Yaxis + 225 (grism dispersion is at PA_dispersion + 135), we want ORIENT = 310. Schedulability is difficult for exactly this orient in the coming campaign, so we have widened the acceptable range to include ORIENT = 280. Note that the POS TARG command is used to position the GRISM so that the continuum spot and 1st and 2nd order all appear on the chip. We would appreciate verification that this is indeed the case. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 CHARON-OLG3 NIC3 MULTIAC NIC3 F150W 1.50000 SAMP-SEQ=STEP2,NSAMP=8 1 DEF POS TARG -10.0, -13.0 Par 60 CUM 2-3 with 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP2,NSAMP=8 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP2,NSAMP=8 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 CHARON-OLG3 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 Par 5-6 60 CUM 0 with 4 ------------------------------------------------------------------------------------------------------------------------------------ 5 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 CHARON-OLG3 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -11.1, -9.0 Par 60 CUM 0 8-9 with 7 ------------------------------------------------------------------------------------------------------------------------------------ 8 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 10 CHARON-OLG3 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 Par 11-12 60 CUM with 10 ------------------------------------------------------------------------------------------------------------------------------------ 11 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 13 CHARON-OLG3 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -10.5, -9.0 Par 60 CUM 14-15 with 13 ------------------------------------------------------------------------------------------------------------------------------------ 14 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 15 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 16 CHARON-OLG3 NIC3 MULTIAC NIC3 G206 2.06700 SAMP-SEQ=STEP16,NSAMP=10,PATTERN 3 DEF pos targ -10,-13 Par 60 CUM = SQUARE-WAVE-DITH,NUM-POS = 4, 17-18 with 16 DITH-SIZE = 3.1 ------------------------------------------------------------------------------------------------------------------------------------ 17 CHARON-OLG3 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP16,NSAMP=10 3 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 18 CHARON-OLG3 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP16,NSAMP=10 3 DEF 60 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 7] Visit: 02 Visit Priority: Visit Requirements: ON HOLD SCHED 70% ORIENT 280D TO 310D On Hold Comments: Until camera 3 focus is stably characterized 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 CHARON-OLG1 NIC3 MULTIAC NIC3 F150W 1.50000 SAMP-SEQ=STEP2,NSAMP=8 1 DEF POS TARG -10.0, -13.0 Par 80 CUM 2-3 with 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP2,NSAMP=8 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 3 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP2,NSAMP=8 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 4 CHARON-OLG1 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 Par 5-6 80 CUM 0 with 4 ------------------------------------------------------------------------------------------------------------------------------------ 5 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7 CHARON-OLG1 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -11.1, -9.0 Par 80 CUM 0 8-9 with 7 ------------------------------------------------------------------------------------------------------------------------------------ 8 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 9 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 10 CHARON-OLG1 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 Par 11-12 80 CUM with 10 ------------------------------------------------------------------------------------------------------------------------------------ 11 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 12 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 13 CHARON-OLG1 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -10.5, -9.0 Par 80 CUM 14-15 with 13 ------------------------------------------------------------------------------------------------------------------------------------ 14 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 15 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP64,NSAMP=13 1 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 16 CHARON-OLG1 NIC3 MULTIAC NIC3 G206 2.06700 SAMP-SEQ=STEP16,NSAMP=10,PATTERN 3 DEF pos targ -10,-13 Par 80 CUM = SQUARE-WAVE-DITH,NUM-POS = 4, 17-18 with 16 DITH-SIZE = 3.1 ------------------------------------------------------------------------------------------------------------------------------------ 17 CHARON-OLG1 NIC1 MULTIAC NIC1 BLANK SAMP-SEQ=STEP16,NSAMP=10 3 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 18 CHARON-OLG1 NIC2 MULTIAC NIC2 BLANK SAMP-SEQ=STEP16,NSAMP=10 3 DEF 80 CUM ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 9] Visit: 03 Visit Priority: Visit Requirements: SCHED 70% ORIENT 160D TO 235D 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 CHARON-OLG9 NIC3 MULTIAC NIC3 F150W 1.50000 SAMP-SEQ=STEP2,NSAMP=8 1 DEF POS TARG -10.0, -13.0 0 CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 CHARON-OLG9 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 0 CUM 0 ------------------------------------------------------------------------------------------------------------------------------------ 3 CHARON-OLG9 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -11.1, -9.0 0 CUM 0 ------------------------------------------------------------------------------------------------------------------------------------ 4 CHARON-OLG9 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 0 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 CHARON-OLG9 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -10.5, -13.0 0 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 CHARON-OLG9 NIC3 MULTIAC NIC3 G206 2.06700 SAMP-SEQ=STEP16,NSAMP=10,PATTERN 3 DEF pos targ -10,-13 0 CUM = SQUARE-WAVE-DITH,NUM-POS = 4, DITH-SIZE = 3.1 ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 10] Visit: 04 Visit Priority: Visit Requirements: SCHED 70% ORIENT 160D TO 235D 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 CHARON-OLG2 NIC3 MULTIAC NIC3 F150W 1.50000 SAMP-SEQ=STEP2,NSAMP=8 1 DEF POS TARG -10.0, -13.0 70 CUM ------------------------------------------------------------------------------------------------------------------------------------ 2 CHARON-OLG2 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 70 CUM 0 ------------------------------------------------------------------------------------------------------------------------------------ 3 CHARON-OLG2 NIC3 MULTIAC NIC3 G096 0.96730 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -11.1, -9.0 70 CUM 0 ------------------------------------------------------------------------------------------------------------------------------------ 4 CHARON-OLG2 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF SAME POS AS 1 70 CUM ------------------------------------------------------------------------------------------------------------------------------------ 5 CHARON-OLG2 NIC3 MULTIAC NIC3 G141 1.41400 SAMP-SEQ=STEP64,NSAMP=13 1 DEF POS TARG -10.5, -13.0 70 CUM ------------------------------------------------------------------------------------------------------------------------------------ 6 CHARON-OLG2 NIC3 MULTIAC NIC3 G206 2.06700 SAMP-SEQ=STEP16,NSAMP=10,PATTERN 3 DEF pos targ -10,-13 70 CUM = SQUARE-WAVE-DITH,NUM-POS = 4, DITH-SIZE = 3.1 ------------------------------------------------------------------------------------------------------------------------------------ 7223( 10) - 02/25/98 15:44 - [ 11] Summary Form for Proposal 7223 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC3 NIC1 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=STEP2 NSAMP=8 NSAMP=13 SAMP-SEQ=STEP64 DITH-SIZE = 3.1 NSAMP=10 SAMP-SEQ=STEP16 NUM-POS = 4 PATTERN = SQUARE-WAVE-DITH ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GTO/NIC ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 70% ORIENT 280D TO 310D POS TARG -10.0, -13.0 Par 2-3 with 1 SAME POS AS 1 Par 5-6 with 4 POS TARG -11.1, -9.0 Par 8-9 with 7 SAME POS AS 1 Par 11-12 with 10 POS TARG -10.5, -9.0 Par 14-15 with 13 pos targ -10,-13 Par 17-18 with 16 ON HOLD SCHED 70% ORIENT 280D TO 310D SCHED 70% ORIENT 160D TO 235D POS TARG -10.0, -13.0 SAME POS AS 1 POS TARG -11.1, -9.0 POS TARG -10.5, -13.0 pos targ -10,-13 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F150W BLANK G096 G141 G206 ------------------------------------------------------------------------------------------------------------------------------------ Target Names CHARON-OLG360 CHARON-OLG180 CHARON-OLG90 CHARON-OLG270 ------------------------------------------------------------------------------------------------------------------------------------