! Proposal 6937, submission 2 ! PI: Massimo Stiavelli ! Received Tue Aug 20 11:47:21 EDT 1996 ! From: shireen@stsci.edu Proposal_Information Title: WFPC2 Cycle 6 CTE Calibration Proposal_Category: CAL/WF2 Scientific_Category: Cycle: 6 Investigators PI_Name: Massimo Stiavelli PI_Institution: STScI Abstract: This program will (1) test whether the exposure time dependence of the photometric calibration is due to CTE (long vs. short exposure problem); (2) refine flux and background-level dependent aperture corrections. Questions Observing_Description: The globular cluster NGC2419 will be observed through F555W with a combination of exposure times (between 5 and 1400s) and preflash levels (0 to 500e). Analysis of cycle 5 CTE calibration (proposal 6192) suggests that magnitude errors due to charge transfer effects are greatly reduced (if not entirely eliminated) at background levels of 160e- or greater. CTE effects have been proposed as the solution to reported differences in the magnitudes of stars measured on frames with short exposures vs. long exposures. If CTE is the cause, then the differences should disappear with preflash. We will reobserve the cluster NGC2419 with and without preflash to test this hypothesis. This dataset will also provide a large number of stars with which to refine existing measurements of the effects of CTE on the wings of the PSF. A range of preflash levels will be explored at the 60 sec exposure time. Real_Time_Justification: Calibration_Justification: Additional_Comments: This program will require 2 orbits (now it really does). Fixed_Targets Target_Number: 1 Target_Name: NGC2419 Alternate_Names: Description: STELLAR CLUSTER, GLOBULAR CLUSTER Position: RA = 7H 38M 6.85S +/- 0.1S,DEC = +38D 51' 55.4" +/- 1",PLATE-ID=01H9 Equinox: 2000 RV_or_Z: RA_PM: Dec_PM: Epoch: Annual_Parallax: Flux:v=10.2 Comments: Visits Visit_Number: 1 Visit_Requirements: ORIENT 259.27D to 279.27D On_Hold_Comments: Visit_Comments: !----- target exptime=60 sec, 80e preflash ----- Exposure_Number: 10 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 16s Special_Requirements: SEQ 10-12 NON-INT Comments: preflash=80e Exposure_Number: 12 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: !-----#1 target exptime=60s, preflash=250e ----- Exposure_Number: 60 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 45s Special_Requirements: SEQ 60-62 NON-INT Comments: preflash=250e Exposure_Number: 62 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: !----- target exptime=60s, preflash=160e, lines 30-32, line 34-36 ----- Exposure_Number: 30 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 30s Special_Requirements: SEQ 30-32 NON-INT Comments: preflash=160e Exposure_Number: 32 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: Exposure_Number: 34 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 30s Special_Requirements: SEQ 34-36 NON-INT Comments: preflash=160e Exposure_Number: 36 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: !----- target exptime=60s, preflash=0e ----- Exposure_Number: 24 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: no preflash !----- target exptime=60s, preflash=160e, lines 70-72 ----- Exposure_Number: 70 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 30s Special_Requirements: SEQ 70-72 NON-INT Comments: preflash=160e Exposure_Number: 72 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: !----- target exptime=60s, preflash=0e ----- Exposure_Number: 78 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60s Special_Requirements: MAX DUR; MIN DUR Comments: no preflash !----- target exptime=1400s, preflash=160e ----- Exposure_Number: 90 Target_Name: INTFLAT Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F502N Wavelength: Optional_Parameters: READ=NO, BLADE=A Number_of_Iterations: 1 Time_Per_Exposure: 30s Special_Requirements: SEQ 90-92 NON-INT Comments: preflash=160e Exposure_Number: 92 Target_Name: NGC2419 Config: WFPC2 Opmode: IMAGE Aperture: PC1-FIX Sp_Element: F555W Wavelength: Optional_Parameters: CR-SPLIT=NO Number_of_Iterations: 1 Time_Per_Exposure: 1400s Special_Requirements: MAX DUR; MIN DUR Comments: Data_Distribution Medium: 8MM Blocking_Factor: 10 Ship_To: PI_Address Ship_Via: UPS Recipient_Email: