Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4161c Report Date: 09-May-96:19:21 Version: ********** Check-in Date: ********** 1.Proposal Title: MAPPING THE POSITION DEPENDENCE OF THE WFPC PSF - VERIFICATION ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID CAL/OTA 3241 Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Roberto Gilmozzi ST SCI USA ------------------------------------------------------------------------------------ 7. Abstract We propose to obtain observations of a bright star at 25 different field locations (a 5 x 5 grid) in WF2, and at 16 different locations (4 x 4 grid) in PC6. These observations will be taken in filters F555W and F785LP (so far the most widely used filters) and will have multiple exposures per readout. The principal aim of this set will be the calibration of the position dependence of the magnitude zero point for photometry. We will also observe (in PC only) through the F487N and F889N filters: this will provide a much needed data set against which to compare the theoretical PSF models. We also plan to take observations in a variety of other filters at 4 locations (2 x 2 grid) in P6, to support recent planetary observations. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 0 10. Num targs pri: 0 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4161c PI: Dr. Roberto Gilmozzi Proposal Title: MAPPING THE POSITION DEPENDENCE OF THE WFPC PSF - VERIFICATION ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Roberto Gilmozzi ST SCI USA X Chris Burrows ST SCI USA X Jon Holzman WF/PC IDT USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. This test is designed to map the structure of the PSF across the field of one chip in each of the WFC and the PC. This information is necessary for several reasons. The variations of the PSF cause variations in the ratio of core light to the total light in a star. In fields with faint stars, only the cores will be visible, so the varying ratio of core to total light must be calibrated by observations of a bright star. These observations will therefore yield a calibration of the position dependence of the magnitude zero point for aperture photometry. In addition, the variations in the PSF cause great complications for deconvolution efforts. We need to be able to understand how the PSF varies, either empirically or through theoretical models. To test any models, however, we need to accumulate an observational database of high S/N PSF images across the field. This proposal will provide such data. We propose to only map one chip in each camera in two filters until we see whether theoretical models can be used. We chose a bright star in order to have exposure times (few tenths of a second) much shorter than the spacecraft jitter time scale (few seconds). This notwithstanding, we will acquire these data in fine lock (for the PC observations), and with high telemetry rates, in order to have a very good assessment of the jitter during each exposure. As an appendix to this program, we will also obtain exposures in a smaller (2 x 2) grid for various other filters in P6. This will support the requirement placed on the TIB calibration plan by recent planetary observations which need appropriate PSF measurements for deconvolution purposes. Since some filters are narrow, the exposure times will not be short enough that the effect of possible enhanced jitter oscillations can be disregarded. However, the use of a 2 x 2 grid strongly enhances the chances that one or more of the exposures will be obtained in an oscillation free period. Moreover, by obtaining PSF measurements at 4 different locations around the center of P6 it will be possible to reach a better understanding of how the PSF varies over the planetary images (which cover a substantial portion of the chip). ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. FOR PC OBSERVATIONS TRY FINE LOCK IF NO GS'S SOON, USE COARSE TRACK. The convention for POS TARGs is the old one (0.0 at the pyramid apex), and the values are slightly different from the ones in the original proposal, 3241. ------------------------------------------------------------------------------------ 11. Address Information Name: ROBERTO GILMOZZI Category: PI Institution: ST SCI Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 4161c [ 3] ------------------------------------------------------------------------------------------------------------------------------------ 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 YOUNG CLUSTER RA = 05H 08M 59S +/-1.0S, 1950 DEC = -68D 49' 24" +/- 5.0" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4161c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 WFC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 SEQ 1.1-1.2 NO GAP PRE-FLASH=YES NON-INT / 1.1-1.2 CYCLE 2 / 1.1-2.5 POS TARG 0,0 Comments: AVOID SAA FOR ALL EXPOSURES. USE SAME GUIDE STARS FOR 1.1- 1.2 IF POSSIBLE. ------------------------------------------------------------------------------------------------------------------------------------ 1.2 NGC1850 WFC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 POS TARG 39,39 PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 2.1 NGC1850 PC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 SEQ 2.1-2.5 NO GAP PRE-FLASH=YES NON-INT / 2.1-2.5 POS TARG 0,0 Comments: AVOID SAA FOR ALL EXPOSURES. USE SAME GUIDE STARS FOR 2.1- 2.5, IF POSSIBLE ------------------------------------------------------------------------------------------------------------------------------------ 2.2 NGC1850 PC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 POS TARG -8,-8 PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 2.3 NGC1850 PC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 POS TARG -8,8 PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 2.4 NGC1850 PC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 POS TARG 8,8 PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ 2.5 NGC1850 PC IMAGE ALL F555W CR-SPLIT=NO 1 300S 1 POS TARG 8,-8 PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4161c [ 5] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC PC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO PRE-FLASH=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal for CAL/OTA ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1.1-1.2 NO GAP; NON-INT / 1.1-1.2; CYCLE 2 / 1.1-2.5; POS TARG 0,0 POS TARG 39,39 SEQ 2.1-2.5 NO GAP; NON-INT / 2.1-2.5; POS TARG -8,-8 POS TARG -8,8 POS TARG 8,8 POS TARG 8,-8 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1850 ------------------------------------------------------------------------------------------------------------------------------------