Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 1083c Report Date: 09-May-96:16:07 Version: ********** Check-in Date: ********** 1.Proposal Title: DYNAMICS OF PLANETARY UPPER ATMOSPHERES ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GTO/HSP Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Robert C. Bless WISCONSIN, UNIVERSITY OF USA 608-262-1715 ------------------------------------------------------------------------------------ 7. Abstract Observations of planetary upper atmospheres through stellar occultations are of interest because they provide information about the radiative and dynamical processes at work in these rarefied regions (number density range: 10super13 - 10super15 cmsuper-3), which could be otherwise measured only through direct atmospheric probe launched from a spacecraft. One of the problems with interpretation of the temperature profiles obtained from ground-based occultation observations has been that the numerical inversion of the data is highly sensitive to photometric errors--especially in obtaining the mean temperature of the atmosphere. The much greater stability of photometry that is possible with the ST will allow us to obtain more accurate temperature profiles and permit a comparison of the atmospheric structures of the Jovian planets with much greater precision than has been possible in the past. We propose a series of three occultation observations for each Jovian ------------------------------------------------------------------------------------ 8. Scientific Key Words: PLANETARY ATMOSPHERES, JOVIAN PLANETS, MARS, UPPER OCCULTATIONS, TEMPERATURE PROFILES ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 10.73 par: 0 10. Num targs pri: 20 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HSP ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. Real Time obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 1083c PI: Robert C. Bless Proposal Title: DYNAMICS OF PLANETARY UPPER ATMOSPHERES ------------------------------------------------------------------------------------ 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 proceeds as follows: 1) Obtain a WFPC image to determine the exact occultation parameters. 2) Acquire occultation candidate using onboard acquisition mode. 3) Scan along the track that the star will follow relative to the planet (along the planetary limb) in order to determine the planetary contribution to the background. 4) Start a continuous series of 10ms integrations enought before the predicted immersion time that scattered light will not affect the acquisition. The occultation observation will require simple tracking on the star before atmosphere immersion, complex tracking on the stellar image as it moves along the planetary limb, and simple tracking after atmosphere emersion. This sequence of integrations must be continuous. 6) Scan along the track that the star will follow relative to the planet. 7) Monitor dark current on ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. We can achieve a much better signal-to-noise ratio for the temperature profiles 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 planetary limb by employing small focal plane apertures; and (iii) the absence of scintillation noise, which has strong components at frequencies comparable to the occultation timescale. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Tracking the occulted star in some cases will require a real time update, due to its complicated path caused by refraction in the occulting planet's atmosphere and the uncertainties in predicting the ST orbit. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. A prior scan over 10 arc-seconds is needed to map the scattered light field, which is needed for the data reduction. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Data will be reduced and analyzed at MIT with the VAX 11-750 belonging to the planetary astronomy group. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Data reduction and analysis will be supported on computer facilities at MIT. Page 3 ------------------------------------------------------------------------------------ 13. Observations of the upper atmospheres of Mars and the Jovian planets with HSP through stellar occultations will provide infromation about the radiative and dynamical processes in this region. The temperature profiles obtained will allow testing of the various transfer models for each planet. ------------------------------------------------------------------------------------ 11. Address Information Name: ROBERT C. BLESS Category: PI Institution: UNIVERSITY OF WISCONSIN Address: DEPARTMENT OF ASTRONOMY City: MADISON State: WI Zip Code: 53706 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Name: JAMES L. ELLIOT Category: CON Institution: MASSACHUSETTS INSTITUTE OF TECHNO Address: BLDG. 54-422 City: CAMBRIDGE State: MA Zip Code: 02139 Country: USA Telephone: 617-253-6308 Telex (or e-mail): 921473 MIT CAM ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 1083c [ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 11 U102 GSC6874 A,140 PLATE-ID = 068E, J2000 BKG 1 V = 13.0 +/- 0.5 -00576 RA = 19H 10M 06.214S +/- 0.1", DEC = -22D 53' 50.97" +/- 0.1", Comments: STAR TO BE OCCULTED BY JUPITER. CLOSE APPROACH AT 8-JUL-92:10:07 SOLAR ELONG 179D ------------------------------------------------------------------------------------------------------------------------------------ 12 U102-OFFSET A,140 PLATE-ID = 068E, J2000 1 B = 11.3 +/- 0.6 GSC6874- RA = 19H 10M 03.659S +/- 00062 0.1", DEC = -22D 53' 05.86" +/- 0.1", Comments: OFFSET TARGET FOR U102 ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 1083c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 20 | TARGET NAME: U102-BACKGROUND ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET URANUS ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = URANUS | TYPE = POS_ANGLE, | RAD = 23.3, | ANG = 82.5, | REF = NORTH | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | | | FOR USE IN A SCAN OF BACKGROUND | | LEVELS ALONG THE PATH OF THE | | OCCULTED STAR | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 21 | TARGET NAME: URANUS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: PLANET URANUS ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = URANUS, ACQ = 0.1 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |V = 5.5 +/- 0.5 | ACQUISITION TARGET FOR BACKGROUND | | SCANS | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1083c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 4 DEFINE # HSP/ ACQ 1 1S 1 1 PCS MODE F ONBRD- VIS ACQ Comments: USE FINE LOCK FOR OFFSET TARGET ACQ IF BRIGHT ENOUGH GUIDE STARS CAN BE FOUND. IF NOT, COARSE TRACK IS ACCEPTABLE. ------------------------------------------------------------------------------------------------------------------------------------ 5 DEFINE # HSP/ ACQ 1 1S 1 1 ONBRD- VIS ACQC ------------------------------------------------------------------------------------------------------------------------------------ 6 DEFINE # HSP/ SPLIT 1.0 F750W/ # 1 1S 1 1 SPATIAL SCAN BACK- PMT/ F320N SCAN VIS Comments: USE FINE LOCK FOR OFFSET TARGET ACQ IF BRIGHT ENOUGH GUIDE STARS CAN BE FOUND. IF NOT, COARSE TRACK IS ACCEPTABLE. ------------------------------------------------------------------------------------------------------------------------------------ 7 DEFINE # HSP/ SPLIT 1.0 F750W/ # 1 1M 1 1 CRIT OBS RING- PMT/ F320N PCS MODE F OCC VIS Comments: USE FINE LOCK FOR OFFSET TARGET ACQ IF BRIGHT ENOUGH GUIDE STARS CAN BE FOUND. IF NOT, COARSE TRACK IS ACCEPTABLE. ------------------------------------------------------------------------------------------------------------------------------------ 10 USE URANUS- X4 ONBOARD ACQ FOR ONBRD- CENTER 10.01 ACQC SEQ 10.00 - 10.01 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 10.01 USE U102- SAMPLE- X135 SEQ 10.01 - 10.03 BACK- BACKGROUND TIME=0.05 GROUP 10.01 - SCAN PRECISION=HIGH 10.04 WITHIN 9H DATA-FORMAT=ALL CYCLE 2/10.00 - PMT- 10.28 ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ 10.02 USE U102- SAMPLE- X135 BACK- BACKGROUND TIME=0.05 SCAN PRECISION=HIGH DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1083c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 10.03 USE U102- SAMPLE- X135 BACK- BACKGROUND TIME=0.05 SCAN PRECISION=HIGH DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ 10.04 USE U102-OFFSET X20 ONBOARD ACQ FOR ONBRD- 10.10 - 10.28 ACQ SEQ 10.04 - 10.10 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 10.1 USE U102 SAMPLE-TIME=0.1 X50 AT 8-JUL-92:09:26 RING- PRECISION=HIGH +/- 1M OCC DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 Comments: END EXPOSURE AT 8-JUL-92:10:50. ------------------------------------------------------------------------------------------------------------------------------------ 10.25 USE URANUS- X4 ONBOARD ACQ FOR ONBRD- CENTER 10.26 ACQC SEQ 10.25-10.26 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 10.26 USE U102- SAMPLE- X135 SEQ 10.26 - 10.28 BACK- BACKGROUND TIME=0.05 GROUP 10.10 - SCAN PRECISION=HIGH 10.28 WITHIN 9H DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ 10.27 USE U102- SAMPLE- X135 BACK- BACKGROUND TIME=0.05 SCAN PRECISION=HIGH DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ 10.28 USE U102- SAMPLE- X135 BACK- BACKGROUND TIME=0.05 SCAN PRECISION=HIGH DATA-FORMAT=ALL PMT- ANALOG=10000 VIS-ANALOG=1000 ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 1083c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 1 Exposure Logsheet lines: 10.01, 10.03, 10.26, FGS Scan: CONTINUOUS Dwell Only: dwell points/line: 0 Seconds per dwell: 0.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 32.6000 Angle between sides (degrees) 90.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0750 PA of first scan line (degrees) 263.000 Scan frame (CEL or S/C): CEL Length Offset (arc-sec): 0. Width Offset (arc-sec): 0. ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 2 Exposure Logsheet lines: 10.02, 10.27 FGS Scan: CONTINUOUS Dwell Only: dwell points/line: 0 Seconds per dwell: 0.00 Scan width (arc-secs): 1.0000 Scan length (arc-secs): 32.6000 Angle between sides (degrees) 90.00 Number of lines: 3 Scan rate (arc-sec/sec): 0.0750 PA of first scan line (degrees) 263.000 Scan frame (CEL or S/C): CEL Length Offset (arc-sec): 0. Width Offset (arc-sec): 0.5000 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 1083c [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HSP/VIS HSP/PMT/VIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SAMPLE-TIME PRECISION DATA-FORMAT PMT-ANALOG VIS-ANALOG ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/HSP ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 10.73 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F; SPATIAL SCAN; CRIT OBS; ONBOARD ACQ FOR 10.01; SEQ 10.00 - 10.01 NO GAP; SEQ 10.01 - 10.03; GROUP 10.01 - 10.04 WITHIN 9H; CYCLE 2/10.00 - 10.28; ONBOARD ACQ FOR 10.10 - 10.28; SEQ 10.04 - 10.10 NO GAP; AT 8-JUL-92 09 26 +/- 1M; ONBOARD ACQ FOR 10.26; SEQ 10.25-10.26 NO GAP; SEQ 10.26 - 10.28; GROUP 10.10 - 10.28 WITHIN 9H; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F750W/F320N ------------------------------------------------------------------------------------------------------------------------------------ Target Names U102 GSC6874-00576 U102-OFFSET GSC6874-00062 U102-BACKGROUND URANUS-CENTER ------------------------------------------------------------------------------------------------------------------------------------