Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4944c Report Date: 09-May-96:20:11 Version: ********** Check-in Date: ********** 1.Proposal Title: OPPORTUNITY OCCULTATIONS BY SMALL BODIES - SPLIT - CYC3HIGH ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GTO/HSP Target of Oppt. 4442 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Robert C. Bless WISCONSIN, UNIVERSITY OF USA (608)262-1715 ------------------------------------------------------------------------------------ 7. Abstract Although an occultation by any specific comet, asteroid, satellite, or Pluto is unlikely to be observable from the ST, the scientific return from such an event would be great because of the superior signal-to-noise ratio achievable with the ST for occultation observations. We propose to observe occultations by these bodies with the ST, as the opportunites arise, to probe their atmospheres, determine their sizes and achieve other goals. With such diverse possibilities, one must examine each opportunity as it occurs and formulate an observing strategy to fit that particular case. Revision History: Recvd on RPS 9/1/89;Added to SCCS 9/5/89; V2 prop instr - SALM; asb@MIT 5/7/90; Small logic errors fixed, BJW 7/9/90; Changed SP SCAN to SP SCAN SING-EXP, BJW 7/10/90; Target changes, ASB; Split by cycle, BJW 4/24/91; Updated targets, BJW 8/1/91; Updated targets, ASB 3/18/92; Cycle 2 changes, ASB 1/24/93 SPLIT FROM 4442 BEC. 2 TARGETS IN 4442 ALREADY EXECUTED; ------------------------------------------------------------------------------------ 8. Scientific Key Words: COMET, ASTEROID, SATELLITE, PLUTO, OCCULTATION ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 1.48 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4944c PI: Robert C. Bless Proposal Title: OPPORTUNITY OCCULTATIONS BY SMALL BODIES - SPLIT - CYC3HIGH ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Edward L. Robinson TEXAS, UNIVERSITY OF USA Robert C. Bless WISCONSIN, UNIVERSITY OF USA G. W. Van Citters NATIONAL SCIENCE FOUNDATION USA Joseph F. Dolan NASA, GODDARD SPACE FLIGHT USA CENTER Richard L. White SPACE TELESCOPE SCIENCE USA INSTITUTE James L. Elliot MASSACHUSETTS INSTITUTE OF USA TECHNOLOGY ------------------------------------------------------------------------------------ 3. Description of proposed observations. We plan to identify those occultations of sufficient signal-to-noise ratio to achieve the goals outlined in Section 2. Each observation will require (i) a set of 2 onboard acquisitions; and (ii) a time series run on the object with whatever filter aperture combination that is chosen for the observation. For some occultations to be observed in the far UV, prior multi-filter photometry of the object will be necessary in order to determine the most appropriate filter to use for the occultation. For now, we shall assume that the calibration and observation time will average about 30 minutes per occultation observed. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. We can achieve a much better signal-to-noise ratio for the temperature profiles and other information than can be obtained for small body occultations than has been possible from the ground for the following reasons: (i) the greatly improved photometric stability of ST photometry, which will substantially reduce the errors in the numerical inversion of the data that is necessary to obtain the temperature profiles; (ii) our ability to reject background light from the occulting object (such as a comet ) by employing small focal plane apertures; and (iii) the absence of scintillation noise, which has strong components at frequencies comparable to the occultation timescale. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data will be reduced and analyzed at MIT with DEC 5000 belonging to the planetary astronomy group. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). TBD ------------------------------------------------------------------------------------ 13. An observation of an occultation by a comet, asteroid, satellite, or Pluto would yield a variety of information. For example, we could gain further information about the atmospheres of Pluto and Triton, including knowledge of the composition and structure of their atmospheres. Also, the presence of possible material in the neighborhood of an asteroid could be obtained. Opportunity stellar occultations by small bodies are proposed to be observed with the HSP or FOS. ------------------------------------------------------------------------------------ 11. Address Information Page 3 Name: ROBERT C. BLESS Category: PI Institution: WISCONSIN, UNIVERSITY OF Address: DEPARTMENT OF ASTRONOMY 475 NORTH CHARTER STREET City: MADISON State: WI Zip Code: 53706 Country: USA Telephone: 608-262-1715 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 4944c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 18 TR46 GSC6310 STAR TO BE OCCULTED BY PLATE-ID = 0104, J2000 BKG 1 R = 13.4 +/- 0.5 -02742 TRITON. RA = 19H 30M 55.294S +/- CLOSE APPROACH AT 13- 0.03", MAY-93:06:46 DEC = -21D 06' 23.79" +/- 0.06", Comments: SOLAR ELONG 121 ------------------------------------------------------------------------------------------------------------------------------------ 19 TR46-OFFSET OFFSET TARGET FOR TR46 PLATE-ID = 0104, J2000 1 R = 14.14 +/- 0.10 GSC6310- RA = 19H 30M 53.111S +/- 01521 0.03", DEC = -21D 06' 04.72" +/- 0.05", ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4944c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 4 DEFINE # HSP/ ACQ 1 1S 1 1 ONBRD- VIS ACQ ------------------------------------------------------------------------------------------------------------------------------------ 7 DEFINE # HSP/ SPLIT 1.0 F750W/ # 1 1M 1 1 RING- PMT/ F320N OCC VIS ------------------------------------------------------------------------------------------------------------------------------------ 7.1 DEFINE ^ S/C DATA NONE FORMAT=FN 1 0S 1 PAR WITH 7.0 RING- OCC Comments: CAPTURE FGS TLM DURING OCCULTATION. ------------------------------------------------------------------------------------------------------------------------------------ 7.2 DEFINE # HSP/ SPLIT 1.0 F750W/ # 1 1M 1 1 RING- PMT/ F320N OCC VIS ------------------------------------------------------------------------------------------------------------------------------------ 7.3 DEFINE ^ S/C DATA NONE FORMAT=FN 1 0S 1 PAR WITH 7.2 RING- OCC Comments: CAPTURE FGS TLM DURING OCCULTATION. ------------------------------------------------------------------------------------------------------------------------------------ 50.04 USE TR46-OFFSET X100 ONBOARD ACQ FOR ONBRD- 50.10 ACQ SEQ 50.04 - 50.10 NO GAP PCS MODE F / 50.04 - 50.10 Comments: USE FINE LOCK FOR OBSERVATION CYCLE 2/50.04 - IF BRIGHT ENOUGH GUIDE STARS 50.10 CAN BE FOUND. IF NOT, COARSE TRACK IS ACCEPTABLE. ------------------------------------------------------------------------------------------------------------------------------------ 50.1 USE TR46 SAMPLE- X30 AT 13-MAY-93:06:21 RING- TIME=0.01 +/- 1M OCC DATA-FORMAT=ALL CRIT OBS PMT-ANALOG=100 VIS-ANALOG=100 Comments: END EXPOSURE AT 13-MAY- 93:07:20. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4944c [ 6] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HSP/VIS HSP/PMT/VIS S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ SPLIT DATA ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FORMAT=FN SAMPLE-TIME DATA-FORMAT PMT-ANALOG VIS-ANALOG ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/HSP ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 1.48 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PAR WITH 7.0; PAR WITH 7.2; ONBOARD ACQ FOR 50.10; SEQ 50.04 - 50.10 NO GAP; PCS MODE F / 50.04 - 50.10; CYCLE 2/50.04 - 50.10; AT 13-MAY-93 06 21 +/- 1M; CRIT OBS; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F750W/F320N ------------------------------------------------------------------------------------------------------------------------------------ Target Names TR46 GSC6310-02742 TR46-OFFSET GSC6310-01521 ------------------------------------------------------------------------------------------------------------------------------------