Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2185c Report Date: 09-May-96:16:56 Version: ********** Check-in Date: ********** 1.Proposal Title: ASTROMETRY VERIFICATIONS AND TESTS; AST-OV-20 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID OV/AST Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Prof. William H. Jeffreys UNIVERSITY OF TEXAS USA (512) 471-4461 ------------------------------------------------------------------------------------ 7. Abstract The goal of this test is to 1) verify that each FGS filter wheel position as commanded actually results from the command. This is required for any observations requiring a filter other than the "clear" filter. 2) verify that the FGSs will be able to observe stars of different magnitudes by using different integration sample times. The test will be coordinated with P-E. Successful conclusion of this test is required for astrometry on objects fainter than the Guide Star limit. 3) determine if objects fainter than the nominal 17.0 magnitude limit can be observed with the FGSs. The nominal limit may be used as a guide line, but the magnitudes may be uncertain by a magnitude. 4) verify that each FGS is capable of performing a Transfer Function Scan and determine an empirical "S" curve. This test is to be coordinated with P-E. 5) verify the ability of the FGSs to obtain astrometric data on a 17th magnitude star which will allow its relative position to be determined to 0.002" in one minute. 6)determine the effects of varying FGE NFES Slope in transiting from coarse track to fine lock, on the statistical nature of the astrometric data, and on the parameters which allow acquisition of astrometric targets with different characteristics. Priorities for FGS Bays 3,1,2 are 1,1,1. These tests should be performed contiguously with the PE test "First Order Plate Scale and FGS/FGS/FGS Alignment. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.50 par: 0 10. Num targs pri: 21 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FGS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2185c PI: Prof. William H. Jeffreys Proposal Title: ASTROMETRY VERIFICATIONS AND TESTS; AST-OV-20 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Astrometry Science Team UNIVERSITY OF TEXAS USA ------------------------------------------------------------------------------------ 2. Scientific Justification. Justifications for each subsection of this test follow: 1) When commanding the Filter Wheel of an FGS, the observer must know which filter goes with which position, and know that the filter wheel will go to the commanded position. 2) The astrometric instrument must be able to take astrometric data on stars at least as faint as 17th magnitude. The operation will require setting the integration exponent to a value other than the default (0). Optimum operation at a given magnitude will require a knowledge of the behavior of the FGSs with different integration sample times. 3) Verify the actual faint limit for astrometry with each FGS unit. 4) Engineering verification of transfer function scan astrometry is required before Science Verification. 5) The position of a 17th magnitude star with respect to other stars in the FGS/FOV to 0.002" is a CEI specification for Astrometry. This test determines how long a measurement is required to obtain what accuracy on a 17th magnitude star for each FGS. 6) Operation of the FGSs for astrometry requires parameters to be set in the FGE. These parameters are uplinked and will vary from default values used for "regular" guiding, and may vary for special guiding problems, as well as astrometric use. We wish to vary the uplink parameter K1 (the NFES Slope of the linear portion of the "S" curve). The optimum value for this slope will depend on the height of the "S" curve, which, in turn, depends on the optical characteristics of each axis of each FGS "as-built," and on the object being observed. An extended object will reduce tha amplitude of the "S" curve, as will another star of whatever magnitude in the 5" square aperture, as will stray light or background nebulosity. Therefore, the effects of changing the slope must be determined for each FGS axis. In some cases, using an incorrect value may reduce efficiency. In others, it may make the difference between obtaining and not obtaining an observation. Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. A) Acquire Guide Stars in FGS 1 and 3. 1) VERIFY FILTER WHEEL a) Set filter position 1 of FGS 2. Acquire a 10th magnitude star with known spectral type with FGS 2. Obtain 1 minute of data including PMT counts on the star with FGS 2. b) Repeat (a) for filter position 2 of FGS 2. c) Repeat (a) for filter position 3 of FGS 2. d) Repeat (a) for filter position 4 of FGS 2. 2) VERIFY INTEGRATION TIMES a) Obtain and measure an 11th magnitude star with i=0 and 1, in FGS 2. b) Obtain and measure a 13th magnitude star with i=1 and 3, in FGS 2. c) Obtain and measure a 15th magnitude star with i=3 and 7, in FGS 2. 3) VERIFY MAGNITUDE LIMITS a) Acquire 17th magnitude star in FGS 2 and take data for 1 min. b) Attempt to acquire 17.5 magnitude star in FGS 2. If successful, take data for 1.5 minute. c) If successful, attempt to acquire 18.0 magnitude star in FGS 2. If successful, take data for 2 minutes. 4) VERIFY TRANSFER FUNCTION SCAN a) Drive FGS 2 to expected location of test star. b) Go into Coarse Track (CT) and determine position of optical centroid. c) Back off at a 45D angle from CT position by (0.50 + 0.25) scan length. d) Ramp up to the scan rate (0.005 arcsec/sec, TBR). e) Scan across the star at 45D, taking data. f) Ramp down to zero rate. 5) TEST ASTROMETRIC ACCURACY ON A 17TH MAGNITUDE STAR IN 1 MIN a) Set on a 17th magnitude star with FGS 2 as Astrometer. b) Obtain FGS data for 5 minutes 6) VERIFY ASTROMETRY WITH DIFFERENT UPLINK PARAMETERS b) Set the K1 for FGS 2 at the default. c) Acquire Reference Star 1 in FGS 2 as Astrometer. d) Take astrometric data for 1 minute. e) Reset the K1 for FGS 2 at about .8 of the default. e) Move astrometer 10 arcsec away from the target by moving the astrometer star selectors. f) Reacquire Reference Star 1 if possible and take data for 1 minute. g) Repeat e and f at about 1.5 of the default. B) Repeat A with FGS 3 as Astrometer. C) Repeat with FGS 1 as Astrometer. N.B. FGS numbers refer to BAY numbers. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. 1) VERIFY FILTER WHEEL OPERATION The star will need ground-based magnitudes and multicolor photometry sufficient to distinguish the various filters. 2) VERIFY INTEGRATION TIMES, 3) VERIFY MAGNITUDE LIMITS, 4) VERIFY TRANSFER, FUNCTION SCAN, 5) TEST THE ASTROMETRIC 17TH MAGNITUDE STAR IN 1 MIN., 6) VERIFY ASTROMETRY WITH DIFFERENT UPLINK PARAMETERS. (Positions to 0.5 arcsec and magnitudes to 0.3 magnitudes will be provided from the ground.) ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. (item 1 re RT branching deleted in 6/16/88 redline) 2) 32 Kbit link. 3) The successful conclusion of subsection 1) of this test is necessary for subsection 3) , subsection 5) , and any observations of stars fainter than the guide star limit. 4) Use astrophysically single stars for subsection 3). The results of subsection 2) are required to properly interpret the results of subsection 3. FGS observations of any object the magnitude of which is 16.5 or fainter will require a knowledge of the results of this test. 5) The successful conclusion of subsection 4) is required for the observations to be performed in AST-OV -8c, AST -SV-3c, and AST-SV-5. It is also required for any Transfer Function Scans or Moving Target Astrometer Ephermeris Track observations to be performed. 6) This test should be performed contiguously with, but separately from the PE test "First Order Plate Scale and FGS/FGS/FGS alignment. 1) The plan is to use stars already calibrated for spectral characteristics. Specific ground-based observations prior to this test may be required. Use 32 Kbit/sec FN format. Data must include all FGS data for the entire observations, not just when "data valid flag" is up. The important information is the detailed transition from coarse track to fine lock. Page 4 ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. 1) The data will be reduced using the ADRS software to determine the observed flux density as a function of filter position. The observed flux density will then be used in combination with the known spectral characteristics of the star plus the measured transmission characteristics of the various filters to determine empirically which filter is in which filter wheel position in each FGS. This table of filter vs. filter wheel position will be inserted into the Project Data Base. 2) ADRS within SDAS will be used to determine centroid and statistical information from the data, to determine the significance of changing the threshhold value of the FGSs. 3) ADRS in SDAS will be used to analyze the data. However, the nature of the test is such that an "on-off" answer essentially characterizes the nature of the test, and will be available from real-time or quick-look data. This test may be performed using P-E specified software to look at the incoming data. (TBR). 4) ADRS within SDAS will be used to derive the observed transfer function and determine whether the scans were conducted correctly. 5) ADRS within SDAS will be used to derive centroid and statistical information for various subsets of the FGS data, and determine the length of time necessary to derive positional accuracy of 0.002" accuracy on a 17th magnitude star. 6) ADRS within SDAS will be used to determine centroid and statistical information from the data, to determine the significance of changing the NFES Slope for the FGSs. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). 1), 2), 3), 5) ADRS will be available in Austin for data reduction. Some personnel will be available to aid in the OV data reduction. Some PDS OV support for Guide Stars is being provided. 4) ADRS will be available in Austin. Double star transfer function analysis software will also be available at the Lowell Observatory (Franz). ------------------------------------------------------------------------------------ 11. Address Information Name: W. H. JEFFERYS Category: PI Institution: UNIVERSITY OF TEXAS Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Name: PETER SHELUS Category: CON Institution: UNIVERSITY OF TEXAS Address: RLM 15.308 City: AUSTIN State: TX Zip Code: 78712 Country: USA Telephone: (512) 471-3339 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2185c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 UPGREN-62 STAR IN NGC188 RA= 00H 37M 11.07S +/- 2.0S, 1950 1 V=9.80 +/- 0.05 DEC= +85D 04' 19.0" +/- 2.0" 2 B=11.33 +/-0.07 ------------------------------------------------------------------------------------------------------------------------------------ 2 UPGREN-69 ^ RA= 00H 37M 51.90S +/- 0.5S, ^ 1 V=9.58 +/- 0.05 DEC= +84D 57' 47.8" +/- 0.5" 2 B=10.08 +/- 0.07 ------------------------------------------------------------------------------------------------------------------------------------ 3 UPGREN-112 STAR IN NGC 188 RA= 00H 40M 58.18S +/- 2S, 1950 1 V= 10.84 +/- 0.05 DEC= +85D 03' 31.1" +/- 2" 2 B= 12.12 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 4 UPGREN-111 ^ RA= 00H 40M 46.26S +/- 2S, ^ 1 V= 12.41 +/- 0.05 DEC= +85D 01' 41.5" +/- 2" 2 B= 13.75 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 5 UPGREN-108 ^ RA= 00H 40M 39.36S +/- 2S, ^ 1 V= 15.03 +/- 0.05 DEC= +85D 02' 12.6" +/- 2" 2 B= 15.72 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 6 SANDAGE-I117 NGC188 STAR RA= 00H 40M 52.61S +/- 2S, ^ 1 V= 17.40 +/- 0.05 DEC= +84D 58' 18.5" +/- 2" 2 B= 18.32 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 7 SANDAGE-I118 NGC188 STAR RA= 00H 41M 13.76S +/- 2S, ^ 1 V= 17.02 +/- 0.05 DEC= +84D 58' 30.8" +/- 2" 2 B= 18.08 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 8 SANDAGE-I166 NGC 188 STAR RA= 00H 43M 38.61S +/- 2S, ^ 1 V= 18.03 +/- 0.05 DEC= +84D 58' 19.6" +/- 2", 2 B= 19.29 +/- 0.05 Comments: TARGETS 6,7, AND 8 MUST BE OBSERVED WITH ONE POINTING/FGS MEASUREMENT ------------------------------------------------------------------------------------------------------------------------------------ 9 UPGREN-138 NGC188 STAR RA= 00H 41M 56.73S +/- 2S, 1950 1 V=14.28 +/- 0.05 DEC= 84D 59' 06.2" +/- 2", 2 B=15.16 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2185c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE UPGREN-62 FGS POS # F583W FES-TIME=0.025 1 1M 1 1 SAME ORIENT FOR 2- AST-FIL DATA-RATE=32 4 AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ ^ ^ ^ ^ F5ND ^ ^ ^ ^ SAME POS FOR 2-4 AS 1 SEQ 1-4 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ ^ ^ ^ ^ F650W ^ ^ ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ ^ ^ ^ ^ F550W ^ ^ ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 11 DEFINE UPGREN-112 FGS POS # F550W FES-TIME=0.025 1 1M 1 1 SAME POS FOR 12-16 INT-TIM DATA-RATE=32 AS 11 ------------------------------------------------------------------------------------------------------------------------------------ 12 ^ ^ ^ ^ ^ ^ FES-TIME=0.05 ^ ^ 1 ^ SAME ORIENT FOR 12 DATA-RATE=32 -16 AS 11 ------------------------------------------------------------------------------------------------------------------------------------ 13 ^ UPGREN-111 ^ ^ ^ ^ ^ ^ ^ 1 ^ SEQ 11-16 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 14 ^ ^ ^ ^ ^ ^ FES-TIME=0.2 ^ ^ 1 ^ DATA-RATE=32 ------------------------------------------------------------------------------------------------------------------------------------ 15 ^ UPGREN-108 ^ ^ ^ ^ ^ ^ ^ 1 ^ ------------------------------------------------------------------------------------------------------------------------------------ 16 DEFINE UPGREN-108 FGS POS # F550W FES-TIME=1.6 1 1M 1 1 INT-TIM DATA-RATE=32 ------------------------------------------------------------------------------------------------------------------------------------ 21 DEFINE SANDAGE- FGS POS # F583W DATA-RATE=32 1 1M 1 1 SAME POS FOR 22-23 MAG-LIM I118 AS 21 SAME ORIENT FOR 22 -23 AS 21 SEQ 21-23 NO GAP ------------------------------------------------------------------------------------------------------------------------------------ 22 ^ ^ SANDAGE- ^ ^ ^ ^ ^ ^ 1.5M 1 1 I117 ------------------------------------------------------------------------------------------------------------------------------------ 23 ^ ^ SANDAGE- ^ ^ ^ ^ ^ ^ 2M 1 1 I166 ------------------------------------------------------------------------------------------------------------------------------------ 31 DEFINE UPGREN-69 FGS TRANS # F583W STEP-SIZE=0.125 1 100S 1 1 FGS-TFN Comments: USE DATA-RATE=32. ------------------------------------------------------------------------------------------------------------------------------------ 51 DEFINE SANDAGE- FGS POS # F583W DATA-RATE=32 1 5M 1 1 STAR-17 I118 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2185c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 61 DEFINE UPGREN-138 FGS POS # F550W FES-TIME=0.025 1 1M 1 1 SEQ 61-63 NO GAP SLOPE DATA-RATE=32 SAME POS FOR 62-63 COUNT=900 AS 61 SAME ORIENT FOR 62 -63 AS 61 Comments: MOVE ASTROMETER STAR SELECTORS TO POSITION THE TARGET AT THE INITIAL POSITION TO START COARSE TRACK, USING COUNT PARAMETER TO FORCE ADJUSTMENT OF K1X AND K1Y. ------------------------------------------------------------------------------------------------------------------------------------ 62 ^ ^ ^ ^ ^ ^ DATA-RATE=32 ^ ^ 1 ^ FES-TIME=0.025 Comments: MOVE ASTROMETER STAR SELECTORS TO POSITION THE TARGET AT THE INITIAL POSITION TO START COARSE TRACK. USING GROUND SYSTEM GENERATED NOMINAL K1 VALUES. ------------------------------------------------------------------------------------------------------------------------------------ 63 ^ ^ ^ ^ ^ ^ DATA-RATE=32 ^ ^ 1 ^ FES-TIME=0.025 COUNT=5200 Comments: MOVE ASTROMETER STAR SELECTORS TO POSITION THE TARGET AT THE INITIAL POSITION TO START COARSE TRACK, USING COUNT PARAMETER TO FORCE ADJUSTMENT OF K1X AND K1Y. ------------------------------------------------------------------------------------------------------------------------------------ 71 USE AST 1 SEQ 71-77 -FIL ------------------------------------------------------------------------------------------------------------------------------------ 72 USE INT 1 -TIM ------------------------------------------------------------------------------------------------------------------------------------ 73 USE MAG 1 -LIM ------------------------------------------------------------------------------------------------------------------------------------ 74 USE FGS 1 -TFN ------------------------------------------------------------------------------------------------------------------------------------ 76 USE 1 STAR-17 ------------------------------------------------------------------------------------------------------------------------------------ 77 USE 1 SLOPE ------------------------------------------------------------------------------------------------------------------------------------ 81 USE AST 2 SEQ 81-87 -FIL ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2185c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 82 USE INT 2 -TIM ------------------------------------------------------------------------------------------------------------------------------------ 83 USE MAG 2 -LIM ------------------------------------------------------------------------------------------------------------------------------------ 84 USE FGS 2 -TFN ------------------------------------------------------------------------------------------------------------------------------------ 86 USE 2 STAR-17 ------------------------------------------------------------------------------------------------------------------------------------ 87 USE 2 SLOPE ------------------------------------------------------------------------------------------------------------------------------------ 91 USE AST 3 SEQ 91-97 -FIL ------------------------------------------------------------------------------------------------------------------------------------ 92 USE INT 3 -TIM ------------------------------------------------------------------------------------------------------------------------------------ 93 USE MAG 3 -LIM ------------------------------------------------------------------------------------------------------------------------------------ 94 USE FGS 3 -TFN ------------------------------------------------------------------------------------------------------------------------------------ 96 USE 3 STAR-17 ------------------------------------------------------------------------------------------------------------------------------------ 97 USE 3 SLOPE ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2185c [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POS ^ TRANS ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FES-TIME=0.025 DATA-RATE=32 FES-TIME=0.05 FES-TIME=0.2 FES-TIME=1.6 STEP-SIZE=0.125 COUNT=900 COUNT=5200 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for OV/AST ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.50 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SAME ORIENT FOR 2-4 AS 1; SAME POS FOR 2-4 AS 1; SEQ 1-4 NO GAP; SAME POS FOR 12-16 AS 11; SAME ORIENT FOR 12-16 AS 11; SEQ 11-16 NO GAP; SAME POS FOR 22-23 AS 21; SAME ORIENT FOR 22-23 AS 21; SEQ 21-23 NO GAP; SEQ 61-63 NO GAP; SAME POS FOR 62-63 AS 61; SAME ORIENT FOR 62-63 AS 61; SEQ 71-77; SEQ 81-87; SEQ 91-97; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F583W F5ND F650W F550W ^ ------------------------------------------------------------------------------------------------------------------------------------ Target Names UPGREN-62 UPGREN-69 UPGREN-112 UPGREN-111 UPGREN-108 SANDAGE-I117 SANDAGE-I118 SANDAGE-I166 UPGREN-138 ------------------------------------------------------------------------------------------------------------------------------------