16862( 2) - 14-Dec-2021 21:12:48 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16862 Version: 2 Check-in Time: 14-Dec-2021 21:12:48 STScI Edit Number: 0 Title Supplemental Empirical CTE Calibrations for Photometry and Astrometry ------------------------------------------------------------------------------------ Type Cycle CAL/WFC3 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jay Anderson Space Telescope Science Institute Y CoI: Benjamin Kuhn Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract WFC3/ISR 2021-13 constructed table-based CTE corrections for photometry and astrometry for backgrounds between 5e and 30e. The astrometric corrections in that ISR were somewhat ad hoc, since the calibration observations were not optimized for astrometry (there were degeneracies at the bright-star end). In this two-orbit program, we will (1) provide photometric corrections all the way up to 100e background, and (2) we will provide explicit astrometric corrections for all background levels, from 10e to 100e. We will use the data collected in this program to update the table-based correction. We will put together a quick ISR to present the analysis and construct the table. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program will involve one two-orbit visit. We will observe the center of Omega Centauri, taking advantage of its flat spatial distribution and its bottom-heavy brightness distribution. The observations will be taken in F502N, which allows efficient 339s exposures to get ~300 stars in the brightest unsaturated magnitude bin, 8000 stars in the S/N~100 magnitude bin, and 20, 000 stars in the faint S/N~10 magnitude bin. We can get 6 such exposures per orbit, for a total of 12 exposures in the program. The natural background of these exposures should be about 10e. We will take 4 exposures with a background of ~60e to provide the photometric and astrometric reference catalogs against which the other background will be measured: (1) one with the null post-targ (centered on the cluster), (2) one with a 1-chip dither upwards in y, (3) one with a -1-chip dither downwards in y, and another with a +0.5 chip dither upwards in y. The two full-dithered steps will allow us to calibrate directly the CTE-related photometric losses in both chips. From this, we will produce an acccurate photometric catalog of all the stars in both chips of the default pointing. The half-chip stepped exposures will allow assessment of the astrometic component of imperfect CTE, which shifts the apparent positions of stars away from the readout register (ie, towards the gap). Since we can get 6 exposures per orbit and 12 total, this leaves us 8 exposures 16862( 2) - 14-Dec-2021 21:12:48 - [ 2] to probe additional backgrounds. We will take one with no postflash, which should probe a background of 10e (thanks to the cluster background), then we'll add 0.1s of MEDIUM current to get 17e, 24e, 31e, 38e, 45e, 52e, (59e), 73e, 80e, and 101e. ------------------------------------------------------------------------------------ 16862( 2) - 14-Dec-2021 21:12:48 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-5139 EXT-CLUSTER, GLOBULAR RA=13H26M47.2400S, J2000 V = 5.33 CLUSTER DEC=-47D28'46.45" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 -3.1959567280703653E-4 -0.006729999904564465 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 16862( 2) - 14-Dec-2021 21:12:48 - [ 4] Visit: 01 Visit Requirements: BEFORE 01-JUN-2022:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.7, 1 350 S (350 POS TARG 0.0, 81.6 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.7, 1 350 S (350 POS TARG 0.0, 40.8 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N GAIN=1.5 1 350 S (350 POS TARG 0.0, 0.00 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.1, 1 350 S (350 POS TARG null, 0.0 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.2, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.3, 1 350 S (350 POS TARG null, 0.0 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.7, 1 350 S (350 POS TARG null, -81.6 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.7, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.4, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.5, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=0.9, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC-5139 WFC3/UVI ACCUM UVIS-CENT F502N FLASHCUR=MEDIUM, FLASHEXP=1.3, 1 350 S (350 S ER GAIN=1.5 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ 16862( 2) - 14-Dec-2021 21:12:48 - [ 5] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC-5139 1 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 2 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 3 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 4 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 5 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 6 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 1 N/A S TER NGC-5139 7 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER NGC-5139 8 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER NGC-5139 9 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER NGC-5139 10 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER NGC-5139 11 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER NGC-5139 12 WFC3/UVI ACCUM UVIS-CEN F502N none none none none 2 N/A S TER 16862( 2) - 14-Dec-2021 21:12:48 - [ 6] Summary Form for Proposal 16862 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASHCUR=MEDIUM, FLASHEXP=0.1, FLASHEXP=0.2, FLASHEXP=0.3, FLASHEXP=0.4, FLASHEXP=0.5, FLASHEXP=0.7, FLASHEXP=0.9, FLASHEXP=1.3, GAIN=1.5 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 01-JUN-2022:00:00:00, POS TARG 0.0, 0.00, POS TARG 0.0, 40.8, POS TARG 0.0, 81.6, POS TARG null, -81.6, POS TARG null, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F502N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC-5139 ------------------------------------------------------------------------------------------------------------------------------------