Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5559 Report Date: 18-Jul-95:17:38 Version: ********** Check-in Date: ********** 1.Proposal Title: WFPC2 ASTROMERTRIC CALIBRATION ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID CAL/WFC Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Roberto Gilmozzi STSCI USA (410)338-4760 SOB BRANCH CHIEF ------------------------------------------------------------------------------------ 7. Abstract The purpose of this calibration test is to determine the plate distortions in the WFPC2 camera. This information is necessary for correctly calculating coordinates used in WFPC2 assisted target acquisition with the small-aperture science instruments and for calibrating WFPC2 astrometric performance. The target field is observed at several overlapping positions so that many stellar separations of various sizes and position angles can be measured in different regions of each CCD. ------------------------------------------------------------------------------------ 8. Scientific Key Words: ASTROMETRIC CALIBRATION OF WFPC2 ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 0 10. Num targs pri: 0 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5559 PI: Dr. Roberto Gilmozzi Proposal Title: WFPC2 ASTROMERTRIC CALIBRATION ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Roberto Gilmozzi STSCI USA Ellyne Kinney STSCI USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. This calibration is crucial for supporting the WFPC2 assisted target acquisitions. It is expected that the WFPC2 will display a substantial geometrical distortion, similar to that of WF/PC, which would impair any astrometry performed with it. Measurements intended for subsequent "blind offsets" with other, small aperture instruments would be particularly affected. Gilmozzi and White (1991) have shown that it is possible to remove the distortion down to a level of 0.01". This type of correction has been successfully applied to WF/PC, and was used to calculate positions for WF/PC assisted target acquistions and to produce geometrically correct mosaics of WF/PC observations. This proposal calibrates the field of view for the three WF chips and the PC chip. To do so we plan to observe a moderately crowded globular cluster in the LMC (NGC1850). The telescope will take an exposure at 10 different positions within the cluster so as to have the same group of stars in each quadrant and in the center of the chip. Comparing the relative positions of the stars in each sector will yield the relative distortion between sectors, which will then be tied together in the central, overlapping area. The outcome of this proposal will be a two-dimensional polynomial which will be used to correct the x,y coordinates of each chip. The observations will be performed in the F569W filter. However, we will check for wavelength dependence of the distortion by taking images in F160BW, F439W and F791W. The use of the same target as in the study of WF/PC will allow us to compare the distortions of the WF/PC to the distortions of the WFPC2. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Instrument calibration. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The prerequsites for this is a calibration activity are that the final telescope focus and collimation be adopted and the observation should be taken in the CVZ. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Avoid the SAA for all exposures. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. These data will be analyzed at STScI and the results will be part of the ScI calibration data base and will be included in WFPC2 Instrument Handbook. ------------------------------------------------------------------------------------ 11. Address Information Name: ROBERTO GILMOZZI Category: PI Institution: STSCI Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Page 3 Name: ELLYNE KINNEY Category: CON Institution: STSCI Address: 3700 SAN MARTIN DR City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: (410)338-4516 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5559 [ 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 NGC1850 J,701 RA = 05H 08M 59S +/-1.0S, 1950 DEC = -68D 49' 24" +/- 5.0" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5559 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 100S 1 CYCLE 4 / 1.1-2.5 ATD-GAIN=15 SEQ 1.1-1.65 NO CR- GAP TOLERANCE=0.0 Comments: AVOID SAA FOR ALL EXPOSURES. USE SAME GUIDE STARS FOR 1.1- 1.8, IF POSSIBLE SCHEDULE DURING CVZ ------------------------------------------------------------------------------------------------------------------------------------ 1.2 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 100S 1 POS TARG 19.5,- ATD-GAIN=15 19.5 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.3 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 100S 1 POS TARG -19.5,- ATD-GAIN=15 19.5 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.4 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 100S 1 POS TARG -19.5, ATD-GAIN=15 19.5 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.5 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 100S 1 POS TARG 19.5,19.5 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.6 NGC1850 WFPC2 IMAGE WFALL F160BW CR-SPLIT=0.7 1 2000S 1 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.65 NGC1850 WFPC2 IMAGE WFALL F170W CR-SPLIT=0.7 1 2000S 1 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.7 NGC1850 WFPC2 IMAGE WFALL F439W CR-SPLIT=0.7 1 1000S 1 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 1.8 NGC1850 WFPC2 IMAGE WFALL F791W CR-SPLIT=0.7 1 1000S 1 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5559 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 2.1 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 200S 1 SEQ 2.1-2.5 NO GAP ATD-GAIN=15 CR- TOLERANCE=0.0 Comments: AVOID SAA FOR ALL EXPOSURES. USE SAME GUIDE STARS FOR 2.1- 2.6, IF POSSIBLE SCHEDULE DURING CVZ ------------------------------------------------------------------------------------------------------------------------------------ 2.2 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 200S 1 POS TARG 8.5,-8.5 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2.3 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 200S 1 POS TARG -8.5,-8.5 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2.4 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 200S 1 POS TARG -8.5,8.5 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2.5 NGC1850 WFPC2 IMAGE WFALL F569W CR-SPLIT=0.7 1 200S 1 POS TARG 8.5,8.5 ATD-GAIN=15 CR- TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5559 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.7 ATD-GAIN=15 CR-TOLERANCE=0.0 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for CAL/WFC ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 4 / 1.1-2.5; SEQ 1.1-1.65 NO GAP; POS TARG 19.5,-19.5 POS TARG -19.5,-19.5 POS TARG -19.5,19.5 POS TARG 19.5,19.5 SEQ 2.1-2.5 NO GAP; POS TARG 8.5,-8.5 POS TARG -8.5,-8.5 POS TARG -8.5,8.5 POS TARG 8.5,8.5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F569W F160BW F170W F439W F791W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1850 ------------------------------------------------------------------------------------------------------------------------------------