Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5633 Report Date: 18-Jul-95:17:46 Version: ********** Check-in Date: ********** 1.Proposal Title: ASTEROID SHAPE AND DUPLICITY ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category MINOR PLANETS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Benjamin Zellner 1780 USA 410-338-4729 ------------------------------------------------------------------------------------ 7. Abstract We here propose a followup of HST Cycle 3 program 4521, a survey program using the Planetary Camera to image about 25 mainbelt minor planets selected as good candidates for extreme shape or duplicity. We propose six generic visits which may be allocated among any objects which were found to be binary in Cycle 3, or other candidates similarly selected on the basis of large-amplitude lightcurves and/or slow rotation. This program was activated in March 1994 for images of asteroid 243 Ida and possible satellites. ------------------------------------------------------------------------------------ 8. Scientific Key Words: IDA ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.8 par: 0 10. Num targs pri: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5633 PI: Dr. Benjamin Zellner Proposal Title: ASTEROID SHAPE AND DUPLICITY ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr. Benjamin Zellner USA Dr. Ed Wells USA Dr. Alex Storrs STSCI USA Dr. David Tholen UNIVERSITY OF HAWAII USA Dr. Clark R. Chapman PLANETARY SCIENCE INSTITUTE USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. Two orbits of observations have been approved: each will be identical to the other. Two images in the blue are made with the F439W filter at a nominal exposure time, followed by two images in the far red (F785LP). Then a third pair of exposures (also with F785LP) are made at a longer exposure time, to maximize the counts from faint nearby companions. This series of six images is repeated after a POS TARG movement of a non-integral number of pixels, both to minimize the effects of local defects and to dither the images for reconstruction. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Only HST provides the sensativity and high spatial resolution to observe the faint companions expected to be seen. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. These observations should be scheduled as soon as possible. The results will be used by the Galileo imaging team in deciding which of their Ida flyby images to read down, and which to destroy. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. The two orbits are requested to be about 8 hours apart, roughly a quarter of what the period of satellite is believed to be. The observations should be made while Ida is at minimum brightness, to minimize the contrast with the satellite. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. This is all being done in a hurry. Please contact Zellner, Wells, Noll, or Storrs with any implementation questions. ------------------------------------------------------------------------------------ 11. Address Information Name: BENJAMIN H. ZELLNER Category: PI Institution: 1780 Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 410-338-4729 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5633 [ 3] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: 243-IDA ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID IDA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = 243 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |V=15.0 +/- 1.0 | | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5633 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 243-IDA WFPC2 IMAGE PC1 F439W READ=1 1 35.0S 1 1 CYCLE 4 CR-SPLIT=NO SEQ 1 - 6 NO GAP PERIOD 2.31682 H + /- 0.00002 H ZERO-PHASE 25-APR- 94:03:22:54 +/- 1S Comments: ASTEROID IDA FIRST VISIT, BLUE PHASE 0.00 +/- FILTER, NOMINAL EXPOSURES. 0.25 NOMINAL EXPOSURE IN F439W IS GUID TOL 0.01" / 1 16.2 SECONDS AT V = 15.0 FOR - 12 2000 DN IN TOTAL IMAGE, MAX 1000 PEAK PIXEL. ZERO-PHASE IS JD 2449467.6270 + 20M light- time. ------------------------------------------------------------------------------------------------------------------------------------ 1.5 243-IDA WFPC2 IMAGE PC1 F439W READ=1 1 35.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA FIRST VISIT, BLUE FILTER, NOMINAL EXPOSURES. NOMINAL EXPOSURE IN F439W IS 16.2 SECONDS AT V = 15.0 FOR 2000 DN IN TOTAL IMAGE, MAX 1000 PEAK PIXEL. SECOND BLUE IMAGE ------------------------------------------------------------------------------------------------------------------------------------ 2 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 5.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA, FIRST VISIT, V FILTER NOMINAL EXPOSURE IN F555W IS 2.4S FOR 2000 DN TOTAL IMAGE, 1000 DN (MAX). EXPOSURE 5.0 SEC SHOULD GIVE 2083 DN PEAK PIX ------------------------------------------------------------------------------------------------------------------------------------ 3 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 10.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA, FIRST VISIT, V FILTER AT V=15.0, 10.0 SEC SHOULD GIVE SLIGHT SATURATION. ------------------------------------------------------------------------------------------------------------------------------------ 4 243-IDA WFPC2 IMAGE PC1 F439W READ=1 2 35S 1 1 CYCLE 4 CR-SPLIT=NO POS TARG 0.452, 0.452 / 4 - 6 Comments: ASTEROID IDA OFFSET, FIRST VISIT, B ------------------------------------------------------------------------------------------------------------------------------------ 5 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 5.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA OFFSET, FIRST VISIT, VIS FILTER, NOMINAL EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5633 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 6 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 10.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA OFFSET, FIRST VISIT, V EXPECT SLIGHT SATURATION. THIS FINISHES FIRST VISIT; 12 EXPOSURES. ------------------------------------------------------------------------------------------------------------------------------------ 7 243-IDA WFPC2 IMAGE PC1 F439W READ=1 1 35.0S 1 1 CYCLE 4 CR-SPLIT=NO SEQ 7 - 12 NO GAP PERIOD 2.31682 H + /- 0.00002 H ZERO-PHASE 25-APR- 94:03:22:54 +/- 1S Comments: ASTEROID IDA, SECOND VISIT, PHASE 0.00 +/- BLUE FILTER. "AFTER 1" 0.25 REQUIREMENT CAN BE RELAXED IF AFTER 1 BY 8H +/- IT PRESENTS SCHEDULING 2H PROBLEMS. FIRST BLUE IMAGE ------------------------------------------------------------------------------------------------------------------------------------ 7.5 243-IDA WFPC2 IMAGE PC1 F439W READ=1 1 35.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA, SECOND VISIT, BLUE FILTER. "AFTER 1" REQUIREMENT CAN BE RELAXED IF IT PRESENTS SCHEDULING PROBLEMS. SECOND BLUE IMAGE ------------------------------------------------------------------------------------------------------------------------------------ 8 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 5.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA, SECOND VISIT, V FILTER, NOMINAL EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ 9 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 10S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA, SECOND VISIT, V FILTER, DEEP EXPOSURE. EXPECT SLIGHT SATURATION. ------------------------------------------------------------------------------------------------------------------------------------ 10 243-IDA WFPC2 IMAGE PC1 F439W READ=1 2 10.0S 1 1 CYCLE 4 CR-SPLIT=NO POS TARG 0.452, 0.452 / 10 - 12 Comments: ASTEROID IDA OFFSET, SECOND VISIT, BLUE FILTER. ------------------------------------------------------------------------------------------------------------------------------------ 11 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 5.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA OFFSET, SECOND VISIT, V FILTER, NOMINAL EXPOSURE ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5633 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 12 243-IDA WFPC2 IMAGE PC1 F555W READ=1 2 10.0S 1 1 CYCLE 4 CR-SPLIT=NO Comments: ASTEROID IDA OFFSET, SECOND VISIT, V FILTER DEEP EXPOSURE. EXPECT SLIGHT SATURATION. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5633 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters READ CR-SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.8 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category MINOR PLANETS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4; SEQ 1 - 6 NO GAP; PERIOD 2.31682 H +/- 0.00002 H ; ZERO-PHASE 25-APR-94 03 22 54 +/- 1S; PHASE 0.00 +/- 0.25; GUID TOL 0.01" / 1 - 12 POS TARG 0.452, 0.452 / 4 - 6 SEQ 7 - 12 NO GAP; AFTER 1 BY 8H +/- 2H POS TARG 0.452, 0.452 / 10 - 12 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F439W F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 243-IDA ------------------------------------------------------------------------------------------------------------------------------------