7319( 13) - 06/30/98 13:35 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7319 Version: 13 Check-in Date: 30-Jun-1998 13:33:55 1.Proposal Title: Composition and Heterogeneity of Io's Volcanos from Polarimetry of Their Thermal Emission ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Jay Goguen JET PROPULSION LABORATORY ------------------------------------------------------------------------------------ 5. Abstract We propose NICMOS measurements of the linear polarization of Io's 2Mum volcanic thermal emission in Jupiter's shadow to study the lava composition and its variation among different hot spots on Io. Goguen and Sinton (1985) used disk- integrated polarimetry of the sunlit Io at 4.8Mum to show that the hot spot emission is strongly polarized and obeys a simple model of polarization by Fresnel transmission across a plane dielectric interface. They deduced both the latitudes and longitudes of hot spots and determined the mean index of refraction of the lava as n=1.51+/- 0.07, consistent with silicate compositions (1.341 km for T>600K. Because locations are measured independently and reflected sunlight is eliminated, the polarization of each hot spot uniquely determines its index of refraction. We expect at least 3-10 hot spots on the visible hemisphere at this level, including Loki. The analysis will focus on the composition and its variation among the hot spots and correlate the variation, for example, with hot spot size, temperature and morphology. ------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 2] Observations Description ------------------------ For 2.3 hours each 42.5 hour orbit, Io passes through Jupiter's shadow, removing the dominant contribution of reflected sunlight from measurements of Io's volcanic thermal emission. Part of each eclipse occurs when Io is occulted by Jupiter's disk, but during a window lasting up to a little over an hour at quadrature, Io's Jupiter-facing hemisphere is directly visible in darkness when essentially all of it's near-IR flux is thermal emission from the volcanic hot spots. During these windows, the polarization of the hot spots will be largest for those sources farthest from the disk center and for those with the largest values of the index of refraction. The exposure times for this experiment are determined by the length of these windows or the HST visibility period, whichever is shorter, and the number of exposures required. At least 3 exposures are needed to measure the polarization and a 4th is desirable at a different wavelength to characterize temperatures and areas of the emitting regions. The duration of these windows is never much larger than a typical HST visibility period of 53 minutes for ecliptic targets, so the highest priority eclipses will be those when a nearly full visibility period of an HST orbit occurs during an eclipse window. Assuming a 53 minute visibiltiy period with Io in-eclipse, a good strategy is to divide the available time minus the overhead between 7 exposures using multiaccumulate readouts to maximize useful dynamic range and small on-chip dithers for sky measurement efficiency. The 7 exposure sequence is composed of 1 exposure at each of the 2 chop positions in each of the 3 polarization filters in NIC2, change to NIC1 and the F145M filter for increased spatial resolution at a shorter wavelength for determination of temperatures and areas. Total overhead would include 6 x 12 sec for setups/filter changes, 20 sec for a 10 arcsec dither, 43 sec for a change from NIC2 to NIC1 for optimum resolution with the F145M filter, 7 x 12 sec for multiaccum mode readouts, plus 10 mins for initial guide star acquisition for a total of 13.7 mins of overhead. This leaves 39 mins to be divided between the 7 science exposures which would then last 5 min = 300 sec each. Using Fig. 5.9 on p. 63 of the NICMOS Instrument Handbook, a 300 sec exposure through the long wavelength polarizers should give a signal- to-noise ratio between 25 and 50 for a 0.1 mJy point source which is the 2Mum flux of a 1 km radius hot spot on Io emitting at 600K or equivalently, a 10 km radius hot spot emitting at 400K. This 2 to 4% precision in the measured flux at each of 3 polarization orientations will allow the expected 5 to 10% or greater polarizations to be measured easily, even for these small and faint hot spots. Of course, the polarization of all brighter hot spots will be measured with correspondingly smaller errors. For comparison, Io's K magnitude in-eclipse is typically 11 or brighter (Silverstone et al., 1995) which corresponds to a flux in excess of 25 mJy, 250 times greater than the anticipated 0.1 mJy flux limit. Similar signal- to-noise is expected for an 0.1 mJy source for a 300 sec exposure through the F145M filter in NIC1. (Note: If the overhead to shift from NIC2 to NIC1 is 7 mins instead of the 43 sec assumed here, the additional overhead would result in the 8 exposures lasting 250 sec each instead of 300 sec each. This would make the expected signal-to-noise ratio for an 0.1 mJy source closer to 25 than to 50 reducing the sensitivity slightly but not changing this analysis or the feasibility significantly.) All 7 exposures are obtained during a single HST orbit visibility period. We will repeat this experiment for 2 separate eclipses during Cycle 7. As the Earth moves along its orbit from pre- opposition to post -opposition quadrature, the sub-earth longitude on Io during its in-eclipse windows of visibility changes by nearly 20 degrees. Because the polarization is a strong function of the emission angle, the Io-centric angle between the sub- earth point on Io and the hot spot location, the polarization of previously measured hot spots will change and sources that were too near the limb to be seen in prior eclipses will be measured during later eclipses. For example, the emission angle at Loki will change from ~40 to 60 degrees from pre-opposition to post-opposition quadrature and as a consequence its polarization is expected to more than double from 4 to 10% is small and measurements at different sub- Earth geometries (disk centers) significantly increases the area of Io's surface and hence the number of hot spots that can be studied by moving sources away from the null-zone at disk center and by rotating new area into view. Measurements of the same hot spot at different emission angles also provides a sensitive test of the model used to interpret the data. The plane dielectric interface model predicts a specific dependence of polarization on emission angle, a prediction that was confirmed in the data and analysis of Goguen and Sinton (1985). Although it is clear that this model works well, at least to first order, the spatially resolved NICMOS measurements will provide a much more stringent test which may lead to refinements that advance the technique. We will observe 2 eclipses to sample this changing geometry: 1 before opposition and 1 after opposition. Real Time Justification ----------------------- These are time-critical eclipse events and care must be exercised in scheduling them. But these eclipses are not rare, as pointed out in the Description section, they occur every 42 hours. Although the availability of suitable eclipses will depend on the beating of the HST orbital period against Io's orbital period, there are a sufficiently large number of Io eclipses that scheduling the proposed observations may not pose unusual scheduling problems. Several programs of observations of Io that may be useful complements to this study are planned and in progress as part of the International Jupiter Watch Program of ground-based observations in support of the Galileo mission. These observations are not essential to this program but may provide useful supplementary data. Valuable additional data is expected from the Galileo mission and infrared measurements of the 1997 series of satellite occultations of Io. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 11 | TARGET NAME: IO-N2BO ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=4.838,ANG=180,REF=NOR | ECL U OF IO BY JUPITER, PHASE OF IO FROM TH | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 8.6", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC2 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 5] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 12 | TARGET NAME: IO-N1BO ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, PHASE OF IO FROM | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 4.5", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC1 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 6] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 13 | TARGET NAME: IO-N2AO ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=4.838,ANG=180,REF=NOR | ECL U OF IO BY JUPITER, PHASE OF IO FROM TH | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 8.6", | OLG OF IO BETWEEN 0 60 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC2 fov, | 5- OLG conforms to AFTER opposition, | not before | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 7] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 14 | TARGET NAME: IO-N1AO ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, PHASE OF IO FROM | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 4.5", | OLG OF IO BETWEEN 0 60 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC1 fov, | 5- OLG conforms to AFTER opposition, | not before | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 8] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 51 | TARGET NAME: IO-N2BO-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=4.838,ANG=180,REF=NOR | ECL U OF IO BY JUPITER, PHASE OF IO FROM TH | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 8.6", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC2 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 9] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 52 | TARGET NAME: IO-N1BO-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, PHASE OF IO FROM | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 4.5", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC1 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 10] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 53 | TARGET NAME: IO-N2AO-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=4.838,ANG=180,REF=NOR | ECL U OF IO BY JUPITER, PHASE OF IO FROM TH | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 8.6", | OLG OF IO BETWEEN 0 60 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC2 fov, | 5- OLG conforms to AFTER opposition, | not before | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 11] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 54 | TARGET NAME: IO-N1AO-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, PHASE OF IO FROM | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 4.5", | OLG OF IO BETWEEN 0 60 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC1 fov, | 5- OLG conforms to AFTER opposition, | not before | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 12] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 61 | TARGET NAME: IO-N2BO-3 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=4.838,ANG=180,REF=NOR | ECL U OF IO BY JUPITER, PHASE OF IO FROM TH | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 8.6", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC2 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 13] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 62 | TARGET NAME: IO-N1BO-3 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=JUPITER | STD=IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ECL U OF IO BY JUPITER, PHASE OF IO FROM | EARTH BETWEEN 7.2 12.0, SIZE IO GT 1.0, | SEP OF IO JUPITER FROM EARTH GT 4.5", | OLG OF IO BETWEEN 300 360 | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | K = 11+/-2 | Window constraints to ensure that 1- | Io is in eclipse and visible, 2- | Phase is large enough that duration | of eclipse is sufficiently long, 3- | Io's angular size is near maximum, 4 | - Jupiter's limb is not in NIC1 fov, | 5- OLG conforms to BEFORE | opposition, not after | ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 14] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: Each visit should be scheduled to include a sufficiently long period of visibility in-eclipse to acquire the NICMOS exposures. This will depend on the beating of Io's and HST's orbital periods and can't be predicted far in advance. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IO-N2BO NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-N2BO NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-N2BO NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-N1BO NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP16,NSAMP=25, 1 DEF CUM PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 15] Visit: 02 Visit Priority: Visit Requirements: SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-N1AO NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP16,NSAMP=25, 1 DEF CUM PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 5 IO-N2AO NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6 IO-N2AO NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 7 IO-N2AO NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 16] Visit: 51 Visit Priority: Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: Each visit should be scheduled to include a sufficiently long period of visibility in-eclipse to acquire the NICMOS exposures. This will depend on the beating of Io's and HST's orbital periods and can't be predicted far in advance. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IO-N2BO-2 NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-N2BO-2 NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-N2BO-2 NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-N1BO-2 NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP16,NSAMP=20, 1 DEF new obset obset id X1 CUM PATTERN=NONE same guide stars 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 17] Visit: 52 Visit Priority: Visit Requirements: SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-N1AO-2 NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP16,NSAMP=25, 1 DEF CUM PATTERN=NONE ------------------------------------------------------------------------------------------------------------------------------------ 5 IO-N2AO-2 NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF new obset obset id X2 CUM X PATTERN=ONE-CHOP,NUM-POS=2, same guide stars 4-7 CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 6 IO-N2AO-2 NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 7 IO-N2AO-2 NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 18] Visit: 61 Visit Priority: Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: Each visit should be scheduled to include a sufficiently long period of visibility in-eclipse to acquire the NICMOS exposures. This will depend on the beating of Io's and HST's orbital periods and can't be predicted far in advance. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 IO-N2BO-3 NIC2 MULTIAC NIC2-FI POL0L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-N2BO-3 NIC2 MULTIAC NIC2-FI POL120L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-N2BO-3 NIC2 MULTIAC NIC2-FI POL240L SAMP-SEQ=STEP256,NSAMP=11, 1 DEF CUM X PATTERN=ONE-CHOP,NUM-POS=2, CHOP-SIZE=9.638, OFFSET=SAM-NO-REACQ, PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-N1BO-3 NIC1 MULTIAC NIC1 F145M SAMP-SEQ=STEP16,NSAMP=20, 1 DEF new obset obset id y1 CUM PATTERN=NONE same guide stars 1-4 ------------------------------------------------------------------------------------------------------------------------------------ 7319( 13) - 06/30/98 13:35 - [ 19] Summary Form for Proposal 7319 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures NIC2-FIX NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 NIC1 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMP-SEQ=STEP256 NSAMP=11 PATTERN=ONE-CHOP NUM-POS=2 CHOP-SIZE=9.638 OFFSET=SAM-NO-REACQ PATTERN-ORIENT=0.0 PATTERN=NONE NSAMP=25 NSAMP=20 SAMP-SEQ=STEP16 PATTERN-ORIENT=90.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% new obset obset id X1 same guide stars 1-4 new obset obset id X2 same guide stars 4-7 new obset obset id y1 same guide stars 1-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements POL0L POL120L POL240L F145M ------------------------------------------------------------------------------------------------------------------------------------ Target Names IO-N2BO IO-N1BO IO-N1AO IO-N2AO IO-N2BO-2 IO-N1BO-2 IO-N1AO-2 IO-N2AO-2 IO-N2BO-3 IO-N1BO-3 ------------------------------------------------------------------------------------------------------------------------------------