Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 1008c Report Date: 09-May-96:16:00 Version: ********** Check-in Date: ********** 1.Proposal Title: TRIGONOMETRIC PARALLAX OF RR LYRAE AND SU CAS ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID STELLAR POPULATIONS GTO/AST 2 Long Term yrs Sub Category ASTROMETRY ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone William H. Jefferys TEXAS, UNIVERSITY OF USA 512-471-4461 PROFESSOR ------------------------------------------------------------------------------------ 7. Abstract The goal of this project is to determine trigonometric parallaxes for RR Lyrae and SU Cas. Both the RR Lyrae stars and the Classical Cepheids are the fundamental distance indicators for the galactic and extragalactic distance scales. Unfortunately, RR Lyrae is the only true RR Lyrae star within the parallax range of the ST. The FGS yields an accuracy of 0.0005 arcsec for the trigonometric parallax, which should provide an accuracy for the absolute magnitude of RR Lyrae of 0.28 mag. SU Cas is nearest Classical Cepheid to us that is also faint enough to observe with the FGS. All other Cepheids are either too bright or too far for an accurate parallax to be determined. We expect that the accuracy of the final absolute magnitude for SU Cas will be 0.35 mag. While neither of these two parallax determinations will be definitive, we feel that the fundamental importance of the distance scale problem demands that we attempt to determine the trigonometric parallaxes of these two stars. ------------------------------------------------------------------------------------ 8. Scientific Key Words: VARIABLES, DISTANCE SCALE, POP I, POP II, PARALLAX, RR LYRAE, CEPHEID, SU CAS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 8.00 par: 0 10. Num targs pri: 22 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FGS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 1008c PI: William H. Jefferys Proposal Title: TRIGONOMETRIC PARALLAX OF RR LYRAE AND SU CAS ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ William H. Jefferys TEXAS, UNIVERSITY OF USA George F. Benedict TEXAS, UNIVERSITY OF USA Raynor L. Duncombe TEXAS, UNIVERSITY OF USA Otto G. Franz LOWELL OBSERVATORY USA Laurence W. Fredrick VIRGINIA, UNIVERSITY OF USA Paul D. Hemenway TEXAS, UNIVERSITY OF USA Peter J. Shelus TEXAS, UNIVERSITY OF USA William F. Van Altena YALE UNIVERSITY USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. Five epochs of observations will be made, each epoch being separated from the other by six months. Each epoch consists of 4 or 6 observations, distributed as follow:4,6,4,6,4, yielding 12 observations on each side of the earth's orbit. The observations extend over a two year period, occurring every six months starting in October 1986. If the launch is delayed then the observation period could start in February 1987. Cycle 1 0.67 hours Cycle 2 3.33 hours Cycle 3 1.67 hours Cycle 4 1.67 hours Cycle 5 0.67 hours ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Ground-based parallaxes are in the very best cases limited to an accuracy of 0.002 arcsec, which is some 4 times poorer than the projected accuracy from the ST. Given the large distances estimated for RR Lyrae and SU Cas, it is impossible to determine an accurate parallax for these stars from the ground even using the best available methods. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Parallax observations must be made during the times when the parallax factor is at a maximum in order to achieve the highest possible accuracy in the parallax. The time tolerance of +/- 21 days in the observation dates is already at the maximum level that is acceptable. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. All of the FGS observations must be uninterrupted in order to minimize the effects of thermal drifts in the ST structure. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. The data reduction will be done with the Astrometric Data Reduction Software developed by the Astrometry Team on computational facilities already available at the home institutions of the Team members. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Computational facilities and the ADRS software package. Page 3 ------------------------------------------------------------------------------------ 12. In order to obtain the highest possible accuracy, it is necessary to operate in a purely differential manner. In the case of the FGS, this means that the target field should always be placed in precisely the same part of the FGS pickle. In this case we are most concerned with local errors in the field distortion and encoders. These errors can be minimized if we are careful to keep our measurements as differential as is possible. To accomplish this we must orient the ST at the same roll angle for each observation at epochs 1, 3 and 5 and 180 degrees from that angle for epochs 2 and 4. Since each observation will take about 10 minutes, it is possible to complete all of the 4 or 6 observations for one epoch during one orbit. ------------------------------------------------------------------------------------ 13. Trigonometric parallaxes will be obtained for the variable stars RR Lyrae and SU CAS. These observations should enable us to determine their absolute magnitudes to an accuracy of about 0.3 mag. and provide a check on their absolute magnitudes determined by other methods. ------------------------------------------------------------------------------------ 11. Address Information Name: WILLIAM H. JEFFERYS Category: PI Institution: UNIVERSITY OF TEXAS Address: ASTRONOMY DEPARTMENT City: AUSTIN State: TX Zip Code: 78712 Country: USA Telephone: 512-471-4461 Telex (or e-mail): ------------------------------------------------------------------------------------ Name: WILLIAM F. VAN ALTENA Category: CON Institution: YALE UNIVERSITY Address: 260 WHITNEY AVENUE City: NEW HAVEN State: CT Zip Code: 06511 Country: USA Telephone: 203-436-8318 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 1008c [ 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 PCENRR PICKLE CENTER FOR RR RA=19H 23M 52.54S +/- 0.1S, 1950 1 V= 10.0 +/- 1.0 LYRAE DEC=+42D 41' 13.3" +/- 1" Comments: THIS TARGET WILL NOT BE MEASURED ------------------------------------------------------------------------------------------------------------------------------------ 2 RR-LYRAE N18 RR-LYRAE RA= 19H 23M 52.25S +/- 0.1S, ^ 1 V=7.9 +/- 0.7 DEC= +42D 41' 12.4" +/- 1" Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B 1950.00 -0.1210 +/- 0.0100 -0.1840 +/- 0.0100 0.0000 +/- 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ 3 AST3-REF N20 REFERENCE STAR FOR RR RA-OFF=-0.1S +/- 0.1S, ^ 1 V=13.9 +/- 1.0 LYRAE DEC-OFF=+72.6" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 4 AST4-REF N22 REFERENCE STAR FOR RR RA-OFF=-10.5S +/- 0.1S, ^ 1 V=15.0 +/- 1.0 LYRAE DEC-OFF=+75.7" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 5 AST5-REF N36 REFERENCE STAR FOR RR RA-OFF=-4.0S +/- 0.1S, ^ 1 V=15.2 +/- 1.0 LYRAE DEC-OFF=+23.9" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 AST6-REF N53 REFERENCE STAR FOR RR RA-OFF=+7.4S +/- 0.1S, ^ 1 V=15.6 +/- 1.0 LYRAE DEC-OFF=+77.5" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 7 AST7-REF N55 REFERENCE STAR FOR RR RA-OFF=+5.3S +/- 0.1S, ^ 1 V=16.5 +/- 1.0 LYRAE DEC-OFF=-33.3" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 8 AST8-REF N56 REFERENCE STAR FOR RR RA-OFF=+2.3S +/- 0.1S, ^ 1 V=14.6 +/- 1.0 LYRAE DEC-OFF=-29.2" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 9 AST9-REF N57 REFERENCE STAR FOR RR RA-OFF=+2.3S +/- 0.1S, ^ 1 V=14.8 +/- 1.0 LYRAE DEC-OFF=-63.9" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 10 AST10-REF REFERENCE STAR FOR RR RA-OFF=+2.5S +/- 0.1S, 1950 1 V=14.7 +/- 1.0 N59 LYRAE DEC-OFF=+115.2" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 11 AST11-REF REFERENCE STAR FOR RR RA-OFF=-6.1S +/- 0.1S, ^ 1 V=14.9 +/- 1.0 N61 LYRAE DEC-OFF=+81.2" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ 12 PCENSU PICKLE CENTER FOR SU RA=2H 47M 27.43S +/- 0.1S, 1950 1 V= 10.0 +/- 1.0 CAS DEC=+68D 38' 52.5" +/- 1" Comments: THIS TARGET WILL NOT BE MEASURED ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 1008c [ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 13 SU-CAS N27 REFERENCE STAR FOR SU RA= 2H 47M 27.86S +/- 0.1S, ^ 1 V=7.1 +/- 0.3 CAS DEC= +68D 40' 56.7" +/- 1" CLASSICAL CEPHEID VARIABLE STAR Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) B 1950.00 0.0050 +/- 0.0040 -0.0070 +/- 0.0030 0.0000 +/- 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ 14 AST14-REF REFERENCE STAR FOR SU RA-OFF=-26.4S +/- 0.1S, ^ 1 V=15.0 +/- 1.0 N32 CAS DEC-OFF=+107.6" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 15 AST15-REF REFERENCE STAR FOR SU RA-OFF=-13.7S +/- 0.1S, ^ 1 V=16.3 +/- 1.0 N33 CAS DEC-OFF=+32.3" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 16 AST16-REF REFERENCE STAR FOR SU RA-OFF=-25.8S +/- 0.1S, ^ 1 V=15.4 +/- 1.0 N34 CAS DEC-OFF=+162.9" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 17 AST17-REF REFERENCE STAR FOR SU RA-OFF=+0.4S +/- 0.1S, ^ 1 V=16.3 +/- 1.0 N35 CAS DEC-OFF=+46.7" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 18 AST18-REF REFERENCE STAR FOR SU RA-OFF=+6.3S +/- 0.1S, ^ 1 V=16.0 +/- 1.0 N36 CAS DEC-OFF=+79.2" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 19 AST19-REF REFERENCE STAR FOR SU RA-OFF=+29.2S +/- 0.1S, ^ 1 V=10.9 +/- 1.0 N44 CAS DEC-OFF=-251.9" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 20 AST20-REF REFERENCE STAR FOR SU RA-OFF=+12.3S +/- 0.1S, 1950 1 V=12.2 +/- 1.0 N45 CAS DEC-OFF=-237.9" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 21 AST21-REF REFERENCE STAR FOR SU RA-OFF=+6.3S +/- 0.1S, ^ 1 V=11.6 +/- 1.0 N46 CAS DEC-OFF=-167.4" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 22 AST22-REF REFERENCE STAR FOR SU RA-OFF=+5.0S +/- 0.1S, ^ 1 V=12.9 +/- 1.0 N50 CAS DEC-OFF=-32.8" +/- 1", FROM 12 ------------------------------------------------------------------------------------------------------------------------------------ 25 AST25-REF REFERENCE STAR FOR RR RA-OFF=+5.2S +/- 0.1S, 1950 1 V=14.1 +/- 1.0 N75 LYRAE DEC-OFF=-207.1" +/- 1", FROM 1 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1008c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 0.5 DEFINE PCENRR FGS POS 2 F5ND DATA-RATE=32 0 53S 35 1 1 SEQ 0.5-12 WITHIN SEQ1 20M SAME POS FOR 1-12 AS 0.5 SAME ORIENT FOR 1- 12 AS 0.5 NON-INT / 0.5-12 ------------------------------------------------------------------------------------------------------------------------------------ 1 DEFINE RR-LYRAE FGS POS 2 F5ND DATA-RATE=32 1 53S 35 1 1 SEQ1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ^ AST3-REF ^ ^ ^ F550W ^ ^ 53S 40 ^ ------------------------------------------------------------------------------------------------------------------------------------ 3 ^ AST4-REF ^ ^ ^ ^ ^ ^ 53S 65 ^ ------------------------------------------------------------------------------------------------------------------------------------ 4 ^ AST5-REF ^ ^ ^ ^ ^ ^ 53S 70 ^ ------------------------------------------------------------------------------------------------------------------------------------ 5 ^ AST6-REF ^ ^ ^ ^ ^ ^ 53S 90 ^ ------------------------------------------------------------------------------------------------------------------------------------ 6 ^ AST7-REF ^ ^ ^ ^ ^ ^ 104S 190 ^ ------------------------------------------------------------------------------------------------------------------------------------ 7 ^ AST8-REF ^ ^ ^ ^ ^ ^ 53S 50 ^ ------------------------------------------------------------------------------------------------------------------------------------ 8 ^ AST9-REF ^ ^ ^ ^ ^ ^ 53S 55 ^ ------------------------------------------------------------------------------------------------------------------------------------ 9 DEFINE AST10-REF FGS POS 2 F550W DATA-RATE=32 1 53S 55 1 1 SEQ1 ------------------------------------------------------------------------------------------------------------------------------------ 10 ^ AST11-REF ^ ^ ^ ^ ^ ^ 53S 60 ^ ------------------------------------------------------------------------------------------------------------------------------------ 11 ^ AST25-REF ^ ^ ^ ^ ^ ^ 53S 42 ^ ------------------------------------------------------------------------------------------------------------------------------------ 12 ^ RR-LYRAE ^ ^ ^ F5ND ^ ^ 53S 35 ^ ------------------------------------------------------------------------------------------------------------------------------------ 13 USE AT 29-APR-90 +/- SEQ1 30D ORIENT 251D +/- 2D REPEAT 13 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 0 ------------------------------------------------------------------------------------------------------------------------------------ 14 USE AT 29-APR-91 +/- SEQ1 30D ORIENT 251D +/- 2D REPEAT 14 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1008c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 15 USE AT 29-APR-92 +/- SEQ1 30D ORIENT 251D +/- 2D REPEAT 15 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ 16 USE AT 28-OCT-90 +/- SEQ1 30D ORIENT 71D +/- 2D REPEAT 16 EVERY 1D +/- 30D FOR 5 MORE TIMES CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 17 USE AT 28-OCT-91 +/- SEQ1 30D ORIENT 71D +/- 2D REPEAT 17 EVERY 1D +/- 30D FOR 5 MORE TIMES CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ 18.5 DEFINE PCENSU FGS POS 2 F5ND DATA-RATE=32 0 53S 30 1 1 SEQ 18.5-30 WITHIN SEQ19 20M SAME POS FOR 19-30 AS 18.5 SAME ORIENT FOR 19 -30 AS 18.5 NON-INT / 18.5-30 ------------------------------------------------------------------------------------------------------------------------------------ 19 DEFINE SU-CAS FGS POS 2 F5ND DATA-RATE=32 1 53S 30 1 1 SEQ19 ------------------------------------------------------------------------------------------------------------------------------------ 20 ^ AST14-REF ^ ^ ^ F550W ^ ^ 53S 65 ^ ------------------------------------------------------------------------------------------------------------------------------------ 21 ^ AST15-REF ^ ^ ^ ^ ^ ^ 104S 160 ^ ------------------------------------------------------------------------------------------------------------------------------------ 22 ^ AST16-REF ^ ^ ^ ^ ^ ^ 53S 80 ^ ------------------------------------------------------------------------------------------------------------------------------------ 23 ^ AST17-REF ^ ^ ^ ^ ^ ^ 104S 160 ^ ------------------------------------------------------------------------------------------------------------------------------------ 24 ^ AST18-REF ^ ^ ^ ^ ^ ^ 104S 120 ^ ------------------------------------------------------------------------------------------------------------------------------------ 25 ^ AST19-REF ^ ^ ^ ^ ^ ^ 53S 30 ^ ------------------------------------------------------------------------------------------------------------------------------------ 26 ^ AST20-REF ^ ^ ^ ^ ^ ^ 53S 30 ^ ------------------------------------------------------------------------------------------------------------------------------------ 27 ^ AST21-REF ^ ^ ^ ^ ^ ^ 53S 30 ^ ------------------------------------------------------------------------------------------------------------------------------------ 28 ^ AST22-REF ^ ^ ^ ^ ^ ^ 53S 33 ^ ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 1008c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 30 DEFINE SU-CAS FGS POS 2 F5ND DATA-RATE=32 1 53S 30 1 1 SEQ19 ------------------------------------------------------------------------------------------------------------------------------------ 31 USE AT 28-AUG-90 +/- SEQ19 30D ORIENT 63D +/- 2D REPEAT 31 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 32 USE AT 28-AUG-91 +/- SEQ19 30D ORIENT 63D +/- 2D REPEAT 32 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ 33 USE AT 28-AUG-92 +/- SEQ19 30D ORIENT 63D +/- 2D REPEAT 33 EVERY 1D +/- 30D FOR 3 MORE TIMES CYCLE 3 ------------------------------------------------------------------------------------------------------------------------------------ 34 USE AT 26-FEB-91 +/- SEQ19 30D ORIENT 243D +/- 2D REPEAT 34 EVERY 1D +/- 30D FOR 5 MORE TIMES CYCLE 1 ------------------------------------------------------------------------------------------------------------------------------------ 35 USE AT 26-FEB-92 +/- SEQ19 30D ORIENT 243D +/- 2D REPEAT 35 EVERY 1D +/- 30D FOR 5 MORE TIMES CYCLE 2 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 1008c [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FGS ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POS ^ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DATA-RATE=32 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GTO/AST ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 8.00 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category STELLAR POPULATIONS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ASTROMETRY ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 0.5-12 WITHIN 20M; SAME POS FOR 1-12 AS 0.5; SAME ORIENT FOR 1-12 AS 0.5; NON-INT / 0.5-12 AT 29-APR-90 +/- 30D; ORIENT 251D +/- 2D; REPEAT 13 EVERY 1D +/- 30D FOR 3 MORE TIMES; CYCLE 0 AT 29-APR-91 +/- 30D; REPEAT 14 EVERY 1D +/- 30D CYCLE 1 AT 29-APR-92 +/- 30D; REPEAT 15 EVERY 1D +/- 30D CYCLE 2 AT 28-OCT-90 +/- 30D; ORIENT 71D +/- 2D; REPEAT 16 EVERY 1D +/- 30D FOR 5 MORE TIMES; AT 28-OCT-91 +/- 30D; REPEAT 17 EVERY 1D +/- 30D SEQ 18.5-30 WITHIN 20M; SAME POS FOR 19-30 AS 18.5; SAME ORIENT FOR 19-30 AS 18.5; NON-INT / 18.5-30 AT 28-AUG-90 +/- 30D; ORIENT 63D +/- 2D; REPEAT 31 EVERY 1D +/- 30D AT 28-AUG-91 +/- 30D; REPEAT 32 EVERY 1D +/- 30D AT 28-AUG-92 +/- 30D; REPEAT 33 EVERY 1D +/- 30D CYCLE 3 AT 26-FEB-91 +/- 30D; ORIENT 243D +/- 2D; REPEAT 34 EVERY 1D +/- 30D AT 26-FEB-92 +/- 30D; REPEAT 35 EVERY 1D +/- 30D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F5ND F550W ^ ------------------------------------------------------------------------------------------------------------------------------------ Target Names PCENRR RR-LYRAE N18 AST3-REF N20 AST4-REF N22 AST5-REF N36 AST6-REF N53 AST7-REF N55 AST8-REF N56 AST9-REF N57 AST10-REF N59 AST11-REF N61 PCENSU SU-CAS N27 AST14-REF N32 AST15-REF N33 AST16-REF N34 AST17-REF N35 AST18-REF AST19-REF N44 AST20-REF N45 AST21-REF N46 AST22-REF N50 AST25-REF N75 ------------------------------------------------------------------------------------------------------------------------------------