Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2923c Report Date: 09-May-96:17:35 Version: ********** Check-in Date: ********** 1.Proposal Title: ASTROMETRY THERMAL TEST ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID OV/2 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone William H. Jefferys TEXAS, UNIVERSITY OF USA 512-471-1455 PROFESSOR ------------------------------------------------------------------------------------ 7. Abstract The Astrometry Science Team will characterize the response of all FGS units to a changing HST thermal environment. By doing this test immediately after the WFPC UV flood test done during a series of "cold" orbits, we can determine changes in FGS behavior with timescales of 4 hours. We can also monitor diurnal changes during the roughly 3 orbits required for this test. ------------------------------------------------------------------------------------ 8. Scientific Key Words: FGS, ASTROMETRY ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.00 par: 0 10. Num targs pri: 4 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FGS ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2923c PI: William H. Jefferys Proposal Title: ASTROMETRY THERMAL TEST ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ William H. Jefferys TEXAS, UNIVERSITY OF USA Peter J. Shelus TEXAS, UNIVERSITY OF USA Paul D. Hemenway TEXAS, UNIVERSITY OF USA Laurence W. Fredrick VIRGINIA, UNIVERSITY OF USA William F. Van Altena YALE UNIVERSITY USA George F. Benedict TEXAS, UNIVERSITY OF USA Raynor L. Duncombe TEXAS, UNIVERSITY OF USA Otto G. Franz LOWELL OBSERVATORY USA ------------------------------------------------------------------------------------ 2. Scientific Justification. The Team beleives that a rigorous thermal characterization of the inter-FGS response to a changing thermal environment is absolutely critical to Astrometry Science. Astrometric measurements at the projected 0.002 arcseconds level of accuracy require intra-FGS measurements within the "Astrometer" FGS. The intra- FGS measurements are made on one object at a time. Thus the relative accuracy of the target with respect to the reference objects depends on the FGS instrumental system remaining fixed on the sky. This depends on the guiding FGSs holding HST fixed with respect to the guide stars, and HST holding the astrometer fixed with respect to the guiding FGSs during the astrometric measuring sequence. Because thermal variations may cause the FGSs to move with respect to each other at the 0.01 arcsecond level, and because we are trying to measure relative positions to 0.002 arcseconds or better, the Astrometry OV thermal test was designed to characterize the amplitudes and timescales for the inter-FGS motions induced by cycling into and out of shadow, and from a worst case thermal slew (hot to cold or cold to hot). Without such a test we can have little confidence in the integrity of our science data, even with some simple "check" measurements in an observing sequence. ------------------------------------------------------------------------------------ 3. Description of proposed observations. Immediately after the WFPC UV Flood Test (proposal 1478) 1) slew to South Ecliptic Pole 2) acquire guide stars 3) acquire first target 4) observe in FGS Pos mode for 3 minutes 5) acquire second target 6) observe in FGS Pos mode for 1 minute 7) acquire third target 8) observe 1 minute 9) acquire fourth target 10) observe 1 minute 11) repeat steps 3-10 20 times ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. We must test the FGS units during HST operations. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. To asses the effects of a changing thermal environment we must stay in "cold" for a reasonable length of time, then remain in a "hot" state. The UV Flood Test is expected to keep the HST in a "cold" state for approximately 5 hours. We wish to keep HST in a "hot" state for the same time duration. Hence, we remain pointed at targets near the South Ecliptic Pole for about 5 hours, repeating observations of our targets. Page 3 ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. TEST MUST IMMEDIATELY FOLLOW WFPC UV FLOOD GUIDE TEST (PROPOSAL 1478) PRESENTLY SCHEDULED IN WEEK 3 OF OV/2 The slew from the anti-sun point (the target for proposal 1478) to the South Ecliptic Pole ( the target for this proposal) should be timed so that the guide star acquisition for 1418 can start at the beginning of the visibilty period. This insures that we begin observing thermal effects as soon as possible. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Guide star and target data will be analyzed to determine magnitude of intra and inter FGS positional changes throughout the approximately 5 hour hot state. We will utilize STScI SDAS (ADRS within SDAS) and models developed to incorporate temporal changes. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Must coordinate with proposal 1478. Must override SAA AVOIDANCE RULE FOR THIS TEST ONLY. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). On site data processing equipment at UTEXAS ------------------------------------------------------------------------------------ 11. Address Information Name: WILLIAM H. JEFFERYS Category: PI Institution: TEXAS, UNIVERSITY OF Address: City: AUSTIN State: TX Zip Code: Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Name: GEORGE F. BENEDICT Category: CON Institution: UNIVERSITY OF TEXAS Address: ASTRONOMY DEPARTMENT City: AUSTIN State: TX Zip Code: 78712 Country: USA Telephone: 512-471-3448 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2923c [ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 THERM1 STAR RA = 05H 53M 01.66S +/- 2000.0 1 V = 13.18 1", DEC = -64D 44' 52.08" +/- 1" Comments: NEW TARGET (5/90) ------------------------------------------------------------------------------------------------------------------------------------ 2 THERM1-1-REF ^ RA = 05H 53M 15.43S +/- ^ 1 V=13.83 1", DEC = -64D 44' 03.48" +/- 1" Comments: NEW TARGET (5/90) ------------------------------------------------------------------------------------------------------------------------------------ 3 THERM1-2-REF ^ RA = 05H 52M 13.56S +/- ^ 1 V=11.77 1", DEC = -64D 43' 40.80" +/- 1" Comments: NEW TARGET (5/90) ------------------------------------------------------------------------------------------------------------------------------------ 4 THERM1-3-REF ^ RA = 05H 53M 43.87S +/- ^ 1 V=14.52 1", DEC = -64D 42M 47.88" +/- 1" Comments: NEW TARGET (5/90) ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2923c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE THERM1 FGS POS 2 F550W DATA-RATE=32 1 3M 1 SEQ 1-2 NON-INT THERMAL CRITICAL OBS NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 DEFINE THERM1-1- ^ ^ ^ ^ ^ ^ 1M NON-INT THERMAL REF DO FOR TARGETS 2-4 ------------------------------------------------------------------------------------------------------------------------------------ 3 USE SEQ 3-22 NO GAP THERMAL Comments: TARGET VISIBILITY PERIOD. TERMINATE TEST AFTER 3 ORBITS. ------------------------------------------------------------------------------------------------------------------------------------ 4 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 5 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 6 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 7 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 8 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 9 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 10 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 11 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 12 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 13 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 14 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 15 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 16 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2923c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 17 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 18 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 19 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 20 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 21 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ 22 USE THERMAL ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2923c [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POS ^ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DATA-RATE=32 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for OV/2 ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1-2 NON-INT; CRITICAL OBS; DO FOR TARGETS 2-4; SEQ 3-22 NO GAP; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F550W ^ ------------------------------------------------------------------------------------------------------------------------------------ Target Names THERM1 THERM1-1-REF THERM1-2-REF THERM1-3-REF ------------------------------------------------------------------------------------------------------------------------------------