16512( 3) - 03-Aug-2021 14:50:03 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16512 Version: 3 Check-in Time: 03-Aug-2021 14:50:03 STScI Edit Number: 0 Title WFC3/IR Time-Dependent Sensitivity in Staring Mode (Clusters) ------------------------------------------------------------------------------------ Type Cycle CAL/WFC3 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Varun Bajaj Space Telescope Science Institute Y CoI: Dr. Annalisa Calamida Space Telescope Science Institute N CoI: Ms. Jennifer Mack Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract The WFC3/IR detector photometric sensitivity is typically characterized by the measurement of isolated, standard spectrophotometric white dwarf stars. To supplement those observations, we seek to measure fluxes of hundreds of stars in stellar clusters over time, to achieve higher precision than using a single star. In this program, we propose to repeat observations from previous observations of M4 (Program 14725) to mitigate effects from different observation configurations. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose two visits of WFC3/IR observations of M4. Both visits will be executed with the same exposure parameters, but will be scheduled approximately 3 months apart, to best sample the time dependence of the sensitivity withtin the window in which the target is visible. Each visit will be composed of 4 exposures, the first two in F110W and the latter two in F160W. The F110W images will use 14 samples with the SPARS50 sample sequence to match those taken in 14725. Due to the shorter orbit duration in 2021 (compared to 14725 in 2017), the latter two exposures will use an NSAMP of 13, to avoid visibility overrun. To mitigate persistence, POSTARGS of 2.5 arcseconds in X and Y will be used between exposures, to match the observations of 14725. ------------------------------------------------------------------------------------ 16512( 3) - 03-Aug-2021 14:50:03 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M-4 STELLAR CLUSTER, RA=16H23M41.7160S, J2000 V = 5.9 GLOBULAR CLUSTER DEC=-26D30'19.01" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16512( 3) - 03-Aug-2021 14:50:03 - [ 3] Visit: 01 Visit Requirements: BETWEEN 20-AUG-2021:00:00:00 AND 15-SEP-2021:00:00:00 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 M-4 WFC3/IR MULTIAC IR-UVIS-F F110W SAMP-SEQ=SPARS50, NSAMP=14 1 DEF POS TARG -5, 5 CUM IX (652.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 M-4 WFC3/IR MULTIAC IR-UVIS-F F110W SAMP-SEQ=SPARS50, NSAMP=14 1 DEF POS TARG -2.5, 2.5 CUM IX (652.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 M-4 WFC3/IR MULTIAC IR-UVIS-F F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF POS TARG 0, 0 CUM IX (602.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 M-4 WFC3/IR MULTIAC IR-UVIS-F F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF POS TARG -7.5, 7.5 CUM IX (602.938 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 | ------------------------------------------------------------------------------------------------------------------------------------ M-4 1 WFC3/IR MULTIAC IR-UVIS- F110W none none none none 1 N/A CUM FIX M-4 2 WFC3/IR MULTIAC IR-UVIS- F110W none none none none 1 N/A CUM FIX M-4 3 WFC3/IR MULTIAC IR-UVIS- F160W none none none none 1 N/A CUM FIX M-4 4 WFC3/IR MULTIAC IR-UVIS- F160W none none none none 1 N/A CUM FIX 16512( 3) - 03-Aug-2021 14:50:03 - [ 4] Visit: 02 Visit Requirements: ORIENT 180D TO 180D FROM 01 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 M-4 WFC3/IR MULTIAC IR-UVIS-F F110W SAMP-SEQ=SPARS50, NSAMP=14 1 DEF POS TARG -5, 5 CUM IX (652.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 M-4 WFC3/IR MULTIAC IR-UVIS-F F110W SAMP-SEQ=SPARS50, NSAMP=14 1 DEF POS TARG -2.5, 2.5 CUM IX (652.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 M-4 WFC3/IR MULTIAC IR-UVIS-F F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF POS TARG 0, 0 CUM IX (602.938 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 M-4 WFC3/IR MULTIAC IR-UVIS-F F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF POS TARG -7.5, 7.5 CUM IX (602.938 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 | ------------------------------------------------------------------------------------------------------------------------------------ M-4 1 WFC3/IR MULTIAC IR-UVIS- F110W none none none none 1 N/A CUM FIX M-4 2 WFC3/IR MULTIAC IR-UVIS- F110W none none none none 1 N/A CUM FIX M-4 3 WFC3/IR MULTIAC IR-UVIS- F160W none none none none 1 N/A CUM FIX M-4 4 WFC3/IR MULTIAC IR-UVIS- F160W none none none none 1 N/A CUM FIX 16512( 3) - 03-Aug-2021 14:50:03 - [ 5] Summary Form for Proposal 16512 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-UVIS-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=13, NSAMP=14, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 20-AUG-2021:00:00:00 AND 15-SEP-2021:00:00:00, ORIENT 180D TO 180D FROM 01, POS TARG -2.5, 2.5, POS TARG -5, 5, POS TARG -7.5, 7.5, POS TARG 0, 0 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M-4 ------------------------------------------------------------------------------------------------------------------------------------