9393( 2) - 02/15/02 10:49 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9393 Version: 2 Check-in Date: 15-Feb-2002 10:48:15 1.Proposal Title: Dynamics and Cloud Structure of Neptune ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Lawrence Sromovsky University of Wisconsin - Madison CoI: Dr. Kevin Baines Jet Propulsion Laboratory N CoI: Dr. Sanjay Limaye University of Wisconsin-Madison N ------------------------------------------------------------------------------------ 5. Abstract A 4-year gap in detailed observation of one of the most active planets in our solar system can be ended by our proposed multispectral WFPC2 imaging of Neptune over a period of 2 Neptune rotations. Our objectives are (1) mapping the two- dimensional distribution of Neptune's discrete cloud features and zonal bands with sufficiently dense longitudinal sampling to insure detection of any Great Dark Spot, or other major storm system, up to 35degrees N, (2) characterizing Neptune's circulation by tracking cloud motions during two densely sampled half-rotations that ensure reliable target identification, and (4) characterizing the vertical structure of clouds by imaging with filters that select varying amounts of Rayleigh scattering and methane absorption and by capturing their center-to-limb variations during intensely sampled feature transits. To enhance the characterization of cloud structure we will also propose coordinated groundbased IRTF and Keck observations, both using adaptive optics at near IR wavelengths that provide access to additional strong methane and hydrogen absorption bands. The proposed HST observations use the same filters as in 1996 and 1998, as well as additional filters, permitting detailed comparisons with previous observations. ------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 2] Observations Description ------------------------ Spatial and Temporal Sampling: We propose relatively dense sampling of two partial rotations of Neptune using 5 successive HST orbits for each half- rotation (relative numbers 1-5, 17-21), constrained mainly by the rules on SAA interference. This approach maximizes tracking accuracy within a single rotation to avoid ambiguities associated with cloud evolution, facilitates tracking of center-to-limb variations, allows more filters to be used at higher exposure levels for the same targets, and assures good coverage at 35degrees N, the last observed location of the post-Voyager dark spot. Because the sub-earth point on Neptune will be at 28.5degrees S at 2002 opposition (2 August), the longitude coverage of a single image is very restricted in the northern hemisphere. Our proposed sampling will obtain coverage adequate to guarantee finding the 35degrees N dark spot, if it still exists. At lower latitudes, where a given longitude will be seen multiple times, speed estimates will be available from the densely sampled rotations, an important feature in a region of rapid cloud evolution. Exposures: we employ 13 filters to sample a wide range of methane band strengths and varying amounts of Rayleigh scattering, sensing a variety of pressure levels. Our spectral imaging sequence provides the highest sampling density for the F467M filter that is needed to identify a high-latitude dark spot. Two visits are used to obtain a total of 70 images. Real Time Justification ----------------------- To facilitate coordinated groundbased observations we prefer that HST observations occur during August 2002 (near opposition on 2 August). Groundbased observations will be proposed as noted in the Science Justification section. Groundbased observations can begin no earlier than 1 August 2002 at Keck and IRTF (start of Fall 2002 semesters). Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: NEPTUNE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET NEPTUNE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=NEPTUNE | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 7.85 | B-V = +0.43 | | ------------------------------------------------------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 01-Aug-2002 AND 01-Sep-2002 On Hold Comments: Additional Comments: Visit 1 is after 1 AUG 2002 due to that being the earliest possible starting date for Fall semester observing at Keck and IRTF. Visit 1 is before 1 SEP 2002 due to desire for coordinated groundbased observations to be as soon as possible after opposition (2 AUG 2002). PC1-FIX aperture used for all exposures to prevent overhead due to retargeting. Location OK for FQCH4P15 due to small size of target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 10-70 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 30 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 40 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 50 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 60 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 70 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 80 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S SEQ 80-140 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 90 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S ------------------------------------------------------------------------------------------------------------------------------------ 100 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 110 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 120 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 130 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 140 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 150 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 150-210 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 160 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 170 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 180 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 190 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 200 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 210 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 220 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S SEQ 220-280 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 230 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S ------------------------------------------------------------------------------------------------------------------------------------ 240 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 250 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 260 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 270 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 280 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 290 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 290-350 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 300 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 310 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 320 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 330 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 340 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 350 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 6] Visit: 02 Visit Priority: Visit Requirements: AFTER 01 BY 15.5 Orbits TO 16.5 Orbits On Hold Comments: Additional Comments: Visit 2 after 1 by 16 orbits to maximize atmospheric feature visibility at several key latitudes. PC1-FIX aperture used for all exposures to prevent overhead due to retargeting. Location OK for FQCH4P15 due to small size of target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 10-70 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 20 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 30 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 40 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 50 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 60 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 70 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 80 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S SEQ 80-140 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 90 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S ------------------------------------------------------------------------------------------------------------------------------------ 100 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 110 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 120 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 130 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 140 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 150 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 150-210 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 160 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 170 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 180 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 190 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 200 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 210 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 220 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S SEQ 220-280 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 230 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S ------------------------------------------------------------------------------------------------------------------------------------ 240 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 250 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 260 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 270 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 280 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 290 NEPTUNE WFPC2 IMAGE PC1-FIX F673N 1 160 S SEQ 290-350 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 300 NEPTUNE WFPC2 IMAGE PC1-FIX F850LP 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 310 NEPTUNE WFPC2 IMAGE PC1-FIX F631N 1 140 S ------------------------------------------------------------------------------------------------------------------------------------ 320 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4N15 6193 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 330 NEPTUNE WFPC2 IMAGE PC1-FIX F467M 1 60 S ------------------------------------------------------------------------------------------------------------------------------------ 340 NEPTUNE WFPC2 IMAGE PC1-FIX FQCH4P15 8929 CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 350 NEPTUNE WFPC2 IMAGE PC1-FIX F953N CLOCKS=YES 1 400 S ------------------------------------------------------------------------------------------------------------------------------------ 9393( 2) - 02/15/02 10:49 - [ 8] Summary Form for Proposal 9393 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-Aug-2002 AND 01-Sep-2002 SEQ 10-70 NON-INT SEQ 80-140 NON-INT SEQ 150-210 NON-INT SEQ 220-280 NON-INT SEQ 290-350 NON-INT AFTER 01 BY 15.5 Orbits TO 16.5 Orbits ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F673N F850LP F631N FQCH4N15 F467M FQCH4P15 F953N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NEPTUNE ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6193 8929 ------------------------------------------------------------------------------------------------------------------------------------