6481( 7) - 04/12/96 16:27 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6481 Version: 7 Check-in Date: 12-Apr-1996 16:08:00 1.Proposal Title: Vesta at Perihelion ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle SOLAR SYSTEM GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Ben Zellner Georgia Southern University CoI: Michael Gaffey Rensselaer Polytechnic Institute N CoI: Alex Storrs Space Telescope Science Institute N CoI: Peter Thomas Cornell University N CoI: Eddie Wells Computer Sciences Corporation N CoI: Rudolph Albrecht Space Telescope ECF N CoI: Richard Binzel Massachusetts Institute of Technology N ------------------------------------------------------------------------------------ 6. Abstract We propose five-color imaging with the Planetary Camera of asteroid 4 Vesta during its near-perihelic opposition in mid- 1996, in order to follow up our successful imaging at a less favorable apparition in 1994. The 1996 apparition of Vesta will be the closest before the year 2007, providing twice the areal resolution of the 1994 data, and will occur at a nearly equatorial aspect. Images during eight HST orbits are requested for good spatial covering of the rotating planet. Five filter passbands ranging from 0.44 to 1.04 microns wavelength are chosen to be diagnostic of the mineralogy and to maximize albedo contrasts. Interpretative techniques are described which will lead to recognition and mapping of pyroxene/feldspar domains indicative of surface lava flows and olivine-rich regions which may be exposed by impact excavation of geologic units originally below a basaltic crust. ------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 2] Observations Description ------------------------ Observational strategy: We propose to obtain resolved Vesta images through five filters at each of eight rotational phases, a strategy used successfully for our Cycle 4 program 5489. Over the HST orbital period of 90 minutes, Vesta rotates by 100 degrees of longitude. Thus features which appear on the meridian within one image sequence will have rotated out of view during the next. Because it is of absolute fundamental importance in our geologic mapping that we establish the reliability of features through rotation, we must have redundant coverage at longitude intervals of 45 degrees or less. Interestingly, the commensurability of Vesta's 5.342 hour rotation period and the HST orbit would allow this coverage to be accomplished in 8 successive orbits. However, only 6 orbits were allocated. We believe that the desired longitude coverage can be obtained with a carefully selected set of orbits. By placing a set of all five filters at the beginning and end of each orbit and grouping the orbits into two 3-orbit visits with the proper separation, images in each filter can be obtained with the desired longitude separation. Scheduling visit 2 either 4, 15, or 16 orbits after visit 1 will give the desired result. The five WFPC2 filters F439W, F673N, F791W, F953N, and F1042M will give us the maximum diagnostic information on Vesta's surface variegation. We will obtain an exposure sequence of 14 Vesta images per HST orbit using single-CCD readouts, The solar phase angle will be around 5 degrees at opposition and will range up to 20 degrees near June 20 1996, but the defect of illumination will remain small. For our currently adopted pole position, the subearth latitude will remain nearly equatorial throughout the observing window. Data analysis: The Cycle 4 observations not only gave us a proven observational strategy as described above, but also served as a testbed for techniques for image processing and reduction to multispectral albedo maps. The data reduction is done by co-investigator Storrs at STScI, and the reduction to surface reflectances by Binzel and Thomas using fully developed tools at Cornell. The images will have SNR exceeding 50, which according to standard practice permits each pixel to be re-sampled into 16 subpixels, increasing the nominal spatial resolution by a factor of four. For deconvolution we use the maximum entropy restoration method, as implemented in the IRAF/STSDAS 'mem' routine. The point- spread function is calculated using the model program 'tinytim' at a 4x- increased spatial scale. Use of this routine produces a smoother restoration than alternative (e.g. Richardson-Lucy) restorations, and is more suitable to broad extended sources such as planetary disks. Richardson-Lucy restorations, by contrast, tend to bring out boundaries of the original pixels, and emphasize noise to an undesirable extent. In the case of the Cycle 4 data, it is notable that the restored images showed substantially more detail than the raw data. With images from the 1996 apparition these methods should resolve features as small as 20 kilometers in diameter. Because of the rapid rotation of Vesta and the finite cycle time of the WFPC2, it is not possible to combine directly images made in different filter passbands. Rather it is necessary first to reduce all images in each wavelength to a common surface projection, which implies a determination of the rotational pole. Pole determination is made by measurement of control points on the surface of Vesta with standard analytic triangulation methods; these are supplemented by using limb and terminator data to determine the aspect angle of the projected short axis, which also depends on pole orientation. The shape model is a 10 by 10 degree latitude, longitude, radius file modified from the best fit ellipsoid to match the indentations visible on Vesta. With the pole determined and the shape model matched to each image, for each pixel in each image we obtain latitude, longitude, incidence, emission, phase, and measured I/F. The I/F values from each image may then be map projected (simple cylindrical or otherwise), and mosaiked. Hapke photometric parameters are fit to the data. The ratio of each pixel to the mean predicted value gives calculated normal reflectances for each pixel, which also can be map projected and mosaiked. In practice, the relative values of normal reflectance calulated are scaled using earth -based data for the absolute values. An important constraint for an extended object is that only the central part of each image is photometrically reliable. In practice the 1994 images were about 5 Planetary Camera pixels in radius, of which only the innermost three pixels could be used in photometric calculations. In 1996 the radius of Vesta will be 7 pixels, giving nearly twice the number of usable pixels per radius and hence much better control of the photometric results. In particular, with images spaced by 45 degrees in rotation, noticeable limb effects survive in our best global mosaics from 1994. With images from the 1996 apparition, such limb effects should disappear. The higher resolution in 1996 in combination with the data already aquired will allow for a refinement of the pole position of Vesta to about 2 degrees uncertainty, and of the shape model to about 10 km uncertainty. With the improved pole and shape, both the old and the new images may be projected into maps and mosaiked. Since the photometric corrections will be good over a larger fraction of the disk than with the 1994 data, our determinations of disk-resolved parameters will allow much improved matching of calculated albedos in the different filters and hence a much improved map of color ratios over the surface. Real Time Justification ----------------------- Vesta will be closest to earth on May 12, 1996. We request that the observations be scheduled before the nominal beginning of Cycle 6; preferably within one week of opposition. However the distance and phase angle will remain acceptable until the end of June. While no supporting observations are required, we will be in close communication with people doing adaptive-optics work on Vesta during this apparition. We expect to exchange results with them freely as we did in 1994. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 4] TARGET LIST b)Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: 4-VESTA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID VESTA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=4(VESTA) | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 5.6+/-0.2 | Target is asteroid 4-Vesta. TYPE=G2V | Observations should be scheduled | within one week of the closest | approach to Earth on May 12, 1996. | Exposures are required for each of | the five filters at longitude | intervals of 45 degrees or less. | ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 5] Visit: 01 Visit Requirements: BETWEEN 05-May-1996 AND 18-May-1996 On Hold Comments: Additional Comments: Observations should be scheduled within 1 week of the opposition of Vesta on May 12, 1996 if possible. To obtain images every 45 deg. of longitude, the second visit should be scheduled 4 orbits after the first. If that fails, the second visit could also be scheduled 15 or 16 orbits after the first. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 1-15 NON-INT GAIN=15,READ=1 Comments: READ=1 is required to prevent tape recorder overflows. The first 5 exposures and last 5 exposures of each orbit are units that should not be interrupted by the start of a new moving target track. ------------------------------------------------------------------------------------------------------------------------------------ 2 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 3 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 4 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 5 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 7 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 9 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 10 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 11 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 12 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 13 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 14 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S END ORBIT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 16 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 16-30 NON-INT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 17 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 18 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 19 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 20 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 22 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 24 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 25 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 26 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 27 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 28 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 29 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 30 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S END ORBIT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 31 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 31-45 NON-INT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 32 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 33 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 34 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 35 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 37 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 39 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 40 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 41 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 42 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 43 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 44 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 45 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 8] Visit: 02 Visit Requirements: AFTER 01 BY 370M TO 400M On Hold Comments: Additional Comments: The AFTER timing requirement will give images in each filter with longitude separations of 45 deg or less. Alternatively, this visit could be scheduled 15 or 16 orbits after the first visit. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 51 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 51-65 NON-INT GAIN=15,READ=1 Comments: All exposures will be made with READ=1. Exposures 1-5 and 11-15 of each erbit are units that should not be interrupted by the start of a new moving target track. ------------------------------------------------------------------------------------------------------------------------------------ 52 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 53 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 54 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 55 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 57 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 59 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 60 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 61 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 62 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 63 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 64 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 65 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S END ORBIT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 9] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 66 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 66-80 NON-INT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 67 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 68 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 69 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 70 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 72 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 74 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 75 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 76 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 77 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 78 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 79 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 80 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S END ORBIT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 81 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S SEQ 81-95 NON-INT GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 82 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 83 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 84 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 10] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 85 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 87 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 89 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 90 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 91 4-VESTA WFPC2 IMAGE PC1 F439W ATD- 1 1.2S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 92 4-VESTA WFPC2 IMAGE PC1 F673N ATD- 1 3.0S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 93 4-VESTA WFPC2 IMAGE PC1 F791W ATD- 1 0.18S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 94 4-VESTA WFPC2 IMAGE PC1 F953N ATD- 1 30S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 95 4-VESTA WFPC2 IMAGE PC1 F1042M ATD- 1 23S GAIN=15,READ=1 ------------------------------------------------------------------------------------------------------------------------------------ 6481( 7) - 04/12/96 16:27 - [ 11] Summary Form for Proposal 6481 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15 READ=1 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 05-May-1996 AND 18-May-1996 SEQ 1-15 NON-INT END ORBIT SEQ 16-30 NON-INT SEQ 31-45 NON-INT AFTER 01 BY 370M TO 400M SEQ 51-65 NON-INT SEQ 66-80 NON-INT SEQ 81-95 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F439W F673N F791W F953N F1042M ------------------------------------------------------------------------------------------------------------------------------------ Target Names 4-VESTA ------------------------------------------------------------------------------------------------------------------------------------