7818( 3) - 02/02/98 10:19 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7818 Version: 3 Check-in Date: 02-Feb-1998 10:17:51 1.Proposal Title: Spectrophotometry of Pluto and Charon ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: MARC BUIE LOWELL OBSERVATORY CoI: William M. Grundy Lowell Observatory N ------------------------------------------------------------------------------------ 5. Abstract We propose high signal-to-noise ratio spectrophotometric observations of Pluto and Charon. These observations will be used to separate the spectroscopic signatures of each object in future ground-based combined light measurements. These spectra will also provide a very sensitive search for trace molecular components on the surfaces of Pluto and Charon. Additional new data will be collected on the methane and water frost spectra in the region usually obscured by telluric water vapor from ground- based measurements. These data will provide an invaluable complementary dataset to our present program of ground-based monitoring of the combined spectra from Pluto and Charon. When combined, these datasets will allow detailed modeling of the distribution and state of voltiles on the surface of Pluto. ------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 2] Observations Description ------------------------ Our program requires observations of Pluto and Charon at four distinct sub- Earth longitudes, 45, 135, 225, and 315 degrees. We are requesting one orbit per longitude which could be scheduled at a minimum of 38.4 hours apart. The position angle of Charon relative to Pluto will determine the roll angle of the spacecraft required to keep the two spectra separate on the detector. The maximum exposure time is set by the brightness of Pluto. At a nominal V=14, Pluto will saturate at about 250-300 seconds. There is a 30% variation in this level caused by Pluto's intrisic lightcurve. During a single orbit, we wish to collect as many spectral images as time allows and while using the YSTRIP-DITH- CHOP pattern using dither and chop offsets of 2 arcsec. We chose MULTIACCUM mode SPARS64 to maximize the number of readouts without losing on-orbit time to dumping the NIC buffer. The dither/chop pattern will help collect information that will permit removal of background flux, cosmic ray hits, and bad pixels. No additional calibration requirements are expected as long as the intended calibration plan is carried out that involves data on a solar type star (P330E). It would be best if such a calibration observation could be scheduled within the same NIC3 campaign. Real Time Justification ----------------------- The only special requirement needed by this proposal concerns the spacecraft roll angle at the time of each observation. The dispersion direction for NIC3/G206 must be coordinated with the spacecraft roll in such a way that the apparent separation between the Pluto and Charon spectra will be significantly greater than the point-spread function. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 3] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: PLCH-045 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON FROM EARTH BETWEEN 125 145 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 13.5+/-0.15 | The desired east longitude is 45D, | the spread given is to provide some | flexibility in scheduling and is not | a hard and fast requirement but is | linked to the ORIENT SR used. A | wider range in CML would lead to a | smaller range on ORIENT. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: PLCH-135 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON FROM EARTH BETWEEN 35 55 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 13.5+/-0.15 | The desired east longitude is 135D, | the spread given is to provide some | flexibility in scheduling and is not | a hard and fast requirement but is | linked to the ORIENT SR used. A | wider range in CML would lead to a | smaller range on ORIENT. | ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: PLCH-225 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON FROM EARTH BETWEEN 305 325 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 13.5+/-0.15 | The desired east longitude is 225D, | the spread given is to provide some | flexibility in scheduling and is not | a hard and fast requirement but is | linked to the ORIENT SR used. A | wider range in CML would lead to a | smaller range on ORIENT. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: PLCH-315 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=PLUTO | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF CHARON FROM EARTH BETWEEN 215 235 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 13.5+/-0.15 | The desired east longitude is 315D, | the spread given is to provide some | flexibility in scheduling and is not | a hard and fast requirement but is | linked to the ORIENT SR used. A | wider range in CML would lead to a | smaller range on ORIENT. | ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 205D TO 265D SCHED 100% On Hold Comments: Additional Comments: The center of the ORIENT range is chosen to maximize the separation of Pluto and Charon in this visit. The range is +/- 30D which keeps the separation larger than 3 pixels. Of course, 180D different from this ORIENT range is okay too but this range is closer to nominal roll. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PLCH-045 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=6 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 20 PLCH-045 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF POS TARG 0.033,1.45 CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=5 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 30 PLCH-045 NIC3 MULTIAC NIC3 F175W SAMP-SEQ=SCAMRR,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 175D TO 215D SCHED 100% On Hold Comments: Additional Comments: The center of the ORIENT range is chosen to maximize the separation of Pluto and Charon in this visit. The range is +/- 20D which keeps the separation larger than 3 pixels. Of course, 180D different from this ORIENT range is okay too but this range is closer to nominal roll. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PLCH-135 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=6 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 20 PLCH-135 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF POS TARG 0.033,1.45 CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=5 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 30 PLCH-135 NIC3 MULTIAC NIC3 F175W SAMP-SEQ=SCAMRR,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 205D TO 265D SCHED 100% On Hold Comments: Additional Comments: The center of the ORIENT range is chosen to maximize the separation of Pluto and Charon in this visit. The range is +/- 30D which keeps the separation larger than 3 pixels. Of course, 180D different from this ORIENT range is okay too but this range is closer to nominal roll. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PLCH-225 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=6 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 20 PLCH-225 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF POS TARG 0.033,1.45 CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=5 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 30 PLCH-225 NIC3 MULTIAC NIC3 F175W SAMP-SEQ=SCAMRR,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 175D TO 215D SCHED 100% On Hold Comments: Additional Comments: The center of the ORIENT range is chosen to maximize the separation of Pluto and Charon in this visit. The range is +/- 20D which keeps the separation larger than 3 pixels. Of course, 180D different from this ORIENT range is okay too but this range is closer to nominal roll. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PLCH-315 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=6 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 20 PLCH-315 NIC3 MULTIAC NIC3 G206 PATTERN=XSTRIP-DITH-CHOP, 1 DEF POS TARG 0.033,1.45 CUM CHOP-SIZE=2.9,DITH-SIZE=0.467, PATTERN-ORIENT=DETECTOR,NUM-POS=5 ,SAMP-SEQ=SPARS64,NSAMP=5 ------------------------------------------------------------------------------------------------------------------------------------ 30 PLCH-315 NIC3 MULTIAC NIC3 F175W SAMP-SEQ=SCAMRR,NSAMP=5 1 DEF CUM ------------------------------------------------------------------------------------------------------------------------------------ 7818( 3) - 02/02/98 10:19 - [ 9] Summary Form for Proposal 7818 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC3 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PATTERN=XSTRIP-DITH-CHOP CHOP-SIZE=2.9 DITH-SIZE=0.467 PATTERN-ORIENT=DETECTOR NUM-POS=6 SAMP-SEQ=SPARS64 NSAMP=5 NUM-POS=5 SAMP-SEQ=SCAMRR ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 205D TO 265D SCHED 100% POS TARG 0.033,1.45 ORIENT 175D TO 215D SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G206 F175W ------------------------------------------------------------------------------------------------------------------------------------ Target Names PLCH-045 PLCH-135 PLCH-225 PLCH-315 ------------------------------------------------------------------------------------------------------------------------------------