! File: 4161C.PROP ! Database: PEPDB ! Date: 20-FEB-1994:11:27:07 coverpage: title_1: MAPPING THE POSITION DEPENDENCE OF THE WFPC PSF - VERIFICATION proposal_for: CAL/OTA cont_id: 3241 pi_title: DR. pi_fname: ROBERTO pi_lname: GILMOZZI pi_inst: ST SCI pi_country: USA wf_pc: Y ! end of coverpage abstract: line_1: We propose to obtain observations of a bright star at 25 different line_2: field locations (a 5 x 5 grid) in WF2, and at 16 different locations line_3: (4 x 4 grid) in PC6. These observations will be taken in filters F555W line_4: and F785LP (so far the most widely used filters) and will have line_5: multiple exposures per readout. The principal aim of this set will be line_6: the calibration of the position dependence of the magnitude zero point line_7: for photometry. We will also observe (in PC only) through the F487N line_8: and F889N filters: this will provide a much needed data set against line_9: which to compare the theoretical PSF models. We also plan to take line_10: observations in a variety of other filters at 4 locations (2 x 2 grid) line_11: in P6, to support recent planetary observations. ! ! end of abstract general_form_proposers: lname: GILMOZZI fname: ROBERTO inst: ST SCI country: USA esa: Y ! lname: BURROWS fname: CHRIS inst: ST SCI country: USA esa: Y ! lname: HOLZMAN fname: JON inst: WF/PC IDT country: USA esa: N ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: This test is designed to map the structure of the PSF across the field line_2: of one chip in each of the WFC and the PC. This information is line_3: necessary for several reasons. The variations of the PSF cause line_4: variations in the ratio of core light to the total light in a star. In line_5: fields with faint stars, only the cores will be visible, so the line_6: varying ratio of core to total light must be calibrated by line_7: observations of a bright star. These observations will therefore yield line_8: a calibration of the position dependence of the magnitude zero point line_9: for aperture photometry. In addition, the variations in the PSF cause line_10: great complications for deconvolution efforts. We need to be able to line_11: understand how the PSF varies, either empirically or through line_12: theoretical models. To test any models, however, we need to accumulate line_13: an observational database of high S/N PSF images across the field. line_14: This proposal will provide such data. line_16: We propose to only map one chip in each camera in two filters until we line_17: see whether theoretical models can be used. ! question: 3 section: 2 line_1: We chose a bright star in order to have exposure times (few tenths of line_2: a second) much shorter than the spacecraft jitter time scale (few line_3: seconds). This notwithstanding, we will acquire these data in fine line_4: lock (for the PC observations), and with high telemetry rates, in line_5: order to have a very good assessment of the jitter during each line_6: exposure. line_8: As an appendix to this program, we will also obtain exposures in a line_9: smaller (2 x 2) grid for various other filters in P6. This will line_10: support the requirement placed on the TIB calibration plan by recent line_11: planetary observations which need appropriate PSF measurements for line_12: deconvolution purposes. Since some filters are narrow, the exposure line_13: times will not be short enough that the effect of possible enhanced line_14: jitter oscillations can be disregarded. However, the use of a 2 x 2 line_15: grid strongly enhances the chances that one or more of the exposures line_16: will be obtained in an oscillation free period. Moreover, by obtaining line_17: PSF measurements at 4 different locations around the center of P6 it line_19: will be possible to reach a better understanding of how the PSF varies line_20: over the planetary images (which cover a substantial portion of the line_21: chip). ! question: 5 section: 1 line_1: FOR PC OBSERVATIONS TRY FINE LOCK IF NO GS'S SOON, USE line_2: COARSE TRACK. The convention for POS TARGs is the old one line_3: (0.0 at the pyramid apex), and the values are slightly line_4: different from the ones in the original proposal, 3241. ! !end of general form text general_form_address: lname: GILMOZZI fname: ROBERTO category: PI inst: ST SCI ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC1850 descr_1: YOUNG CLUSTER pos_1: RA = 05H 08M 59S +/-1.0S, pos_2: DEC = -68D 49' 24" +/- 5.0" equinox: 1950 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.100 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 1.1-1.2 NO GAP; req_2: NON-INT / 1.1-1.2; req_3: CYCLE 2 / 1.1-2.5; req_4: POS TARG 0,0 comment_1: AVOID SAA FOR ALL EXPOSURES. comment_2: USE SAME GUIDE STARS FOR 1.1-1.2 comment_3: IF POSSIBLE. ! linenum: 1.200 targname: NGC1850 config: WFC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG 39,39 ! linenum: 2.100 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: SEQ 2.1-2.5 NO GAP; req_2: NON-INT / 2.1-2.5; req_3: POS TARG 0,0 comment_1: AVOID SAA FOR ALL EXPOSURES. comment_2: USE SAME GUIDE STARS FOR 2.1-2.5, comment_3: IF POSSIBLE ! linenum: 2.200 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -8,-8 ! linenum: 2.300 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG -8,8 ! linenum: 2.400 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG 8,8 ! linenum: 2.500 targname: NGC1850 config: PC opmode: IMAGE aperture: ALL sp_element: F555W num_exp: 1 time_per_exp: 300S priority: 1 param_1: CR-SPLIT=NO, param_2: PRE-FLASH=YES req_1: POS TARG 8,-8 ! ! end of exposure logsheet ! No scan data records found