18419( 2) - 19-Aug-2026 10:45:14 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18419 Version: 2 Check-in Time: 19-Aug-2026 10:45:14 STScI Edit Number: 0 Title Anchoring Mira Distance Ladder: Bridging Ground-Based, Optical, and Next-Generation Observations with WFC3/IR ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Caroline Huang Smithsonian Institution Astrophysical Y Observatory CoI: Mr. Antonio Capodagli Florida State University N CoI: Dr. Louise Breuval Space Telescope Science Institute - ESA N CoI: Dr. Stefano Casertano Space Telescope Science Institute N CoI: Dr. Geza Csornyei European Southern Observatory - Germany N CoI: Dr. Lucas M. Macri University of Texas Rio Grande Valley N CoI: Dr. Massimo Marengo Florida State University N CoI: Dr. Marina Rejkuba European Southern Observatory - Germany N CoI: Dr. Adam Riess The Johns Hopkins University N CoI: Dr. Wenlong Yuan The Johns Hopkins University N ------------------------------------------------------------------------------------ Abstract The discrepancy between the local and early-Universe measurements of the Hubble constant (H0) remains a key unresolved issue in cosmology. The tension has grown even more robust in recent joint analysis from the Local Distance Network collaboration, with a baseline result 7.1sigma from the early Universe + LambdaCDM value, hinting at missing physics beyond the standard model. In this networked approach, reducing reliance on any single method requires robust cross-checks between independent indicators. Luminous, oxygen-rich Mira variables are uniquely positioned to provide these vital cross-checks across all distances and host environments. To maximize the utility of HST's archival WFC3/IR data before the instrument's eventual decommissioning, we propose new, multi-epoch observations of three nearby galaxies: NGC 4258, NGC 5128, and M51. Combined with archival data, this program will 1) extend and improve the absolute calibration of the Mira Period-Luminosity Relation, 2) bridge HST and ground-based IR filter systems, 3) demonstrate the feasibility of obtaining Mira distances across diverse galaxy environments, and 4) conduct a novel cross-checks against Cepheids, TRGB, and the Type IIP supernova expanding photosphere method. Because neither JWST nor Roman can replicate Hubble's observational flexibility and cadence for nearby resolved stellar populations, this program represents an essential, time-sensitive investment to finalize the Mira distance scale. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program consists of a total of 33 orbits divided between Cycle 34 (22 orbits) and Cycle 35 (11 orbits). We will target 3 galaxies: M51, Cen A, and NGC 4258. The observations are designed to synergize with the existing archival 18419( 2) - 19-Aug-2026 10:45:14 - [ 2] observations while allowing as large of visibility windows as possible. In order to recover periods precisely, we have designated the necessary timing requirements in the observation setups. All observations will be made with WFC3/IR and do not have any orientation angle constraints. Targets are resolved stellar populations in nearby galaxies. NGC 4258 and M51 are located at ~ 7 Mpc, and thus we will observe only F160W to increase the recovery of fainter, shorter-period stars. Cen A, which is at ~3.5 Mpc will be observed in both F160W and F110W to add broadband color information. Cycle 34 Observations NGC 4258: 1 field which will be observed in 5 epochs, each consisting of 1 orbit. Observations will utilize a four-point dither pattern and F160W filter. Observations will have a semi-logarithmic spacing to reduce potential aliasing, while also recovering shorter periods more accurately. Cen A: 2 fields (F1 and F2, based on the designations from Rejkuba+2003a, b and 2004), each with 5 epochs, consisting of 1 orbit (a total of 10 epochs/orbits). Observations will utilize a four-point dither pattern and F160W and F110W filters. Observations will be spaced approximately monthly over the course of the year during visibility windows. M51: 1 field which will be observed in 7 epochs each consisting of 1 orbit. Observations will utilize a four-point dither pattern and F160W filter. Observations will have roughly monthly spacing over the course of a year. Cycle 35 Observations NGC 4258: No observations in Cycle 35. Cen A: 2 fields observed in 3 epochs consisting of 1 orbit each (a total of 6 orbits). Observations will utilize a four-point dither pattern and F160W and F110W filters. Observing over Cycle 34 and 35 will improve the baseline for long-period variables. M51: 1 field observed in 5 epochs, consisting of 1 orbit each for a total of 5 orbits. Observations will utilize a four-point dither pattern and F160W filter. Combined with Cycle 34 observations these will result in an improved long-period variable baseline. ------------------------------------------------------------------------------------ 18419( 2) - 19-Aug-2026 10:45:14 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4258-INNE GALAXY, DISK, SPIRAL, RA=12H18M47.5140S, J2000 V = 8.41 R SPIRAL ARM DEC=+47D20'20.25" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 GALAXY, ELLIPTICAL, RA=13H26M23.5000S, J2000 V = 6.84 LENTICULAR DEC=-42D52'0.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 CEN-A-F2 GALAXY, ELLIPTICAL, RA=13H25M24.0000S, J2000 V = 6.84 LENTICULAR DEC=-43D10'0.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 4 M-51 GALAXY, DISK, SPIRAL, RA=13H29M59.0000S, J2000 V = 8.36 SPIRAL ARM DEC=+47D11'12.69" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 18419( 2) - 19-Aug-2026 10:45:14 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18419( 2) - 19-Aug-2026 10:45:14 - [ 5] Visit: 01 (Visit 1, NGC 4258) Visit Requirements: BEFORE 01-DEC-2026:00:00:00 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 NGC4258-INN WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 ER CUM (2411.751 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 6] Visit: 02 (Visit 2, NGC 4258) Visit Requirements: AFTER 01 BY 20 D TO 40 D 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 NGC4258-INN WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 ER CUM (2411.751 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 7] Visit: 03 (Visit 3, NGC 4258) Visit Requirements: AFTER 01 BY 100 D TO 120 D 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 NGC4258-INN WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 ER CUM (2411.751 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 8] Visit: 04 (Visit 4, NGC 4258) Visit Requirements: AFTER 01 BY 170 D TO 220 D 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 NGC4258-INN WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 ER CUM (2411.751 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 9] Visit: 05 (Visit 5, NGC 4258) Visit Requirements: AFTER 01 BY 300 D TO 365 D 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 NGC4258-INN WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 ER CUM (2411.751 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM NGC4258-INNER 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 10] Visit: 06 (Visit 1, Cen A F1) Visit Requirements: BEFORE 31-DEC-2026:00:00:00 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 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 11] Visit: 07 (Visit 2, Cen A F1) Visit Requirements: AFTER 06 BY 5 D TO 30 D 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 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 12] Visit: 08 (Visit 3, Cen A F1) Visit Requirements: AFTER 07 BY 20 D TO 110 D 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 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 13] Visit: 09 (Visit 4, Cen A F1) Visit Requirements: AFTER 08 BY 20 D TO 110 D 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 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 14] Visit: 10 (Visit 5, Cen A F1) Visit Requirements: AFTER 09 BY 20 D TO 110 D 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 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F1 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F1 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F1 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 15] Visit: 11 (Visit 1, Cen A F2) Visit Requirements: BEFORE 31-DEC-2026:00:00:00 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 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 16] Visit: 12 (Visit 2, Cen A F2) Visit Requirements: AFTER 11 BY 5 D TO 30 D 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 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 17] Visit: 13 (Visit 3, Cen A F2) Visit Requirements: AFTER 12 BY 20 D TO 110 D 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 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 18] Visit: 14 (Visit 4, Cen A F2) Visit Requirements: AFTER 13 BY 20 D TO 110 D 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 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 19] Visit: 15 (Visit 5, Cen A F2) Visit Requirements: AFTER 14 BY 20 D TO 110 D 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 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS25, NSAMP=13 1 DEF PATTERN 1 1-2 CUM (1211.754 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CEN-A-F2 WFC3/IR MULTIAC IR-FIX F110W SAMP-SEQ=SPARS25, NSAMP=12 1 DEF CUM (1111.752 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 | ------------------------------------------------------------------------------------------------------------------------------------ CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM CEN-A-F2 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 1 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 2 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 3 none none none 1 N/A CUM CEN-A-F2 2 WFC3/IR MULTIAC IR-FIX F110W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 20] Visit: 16 (Visit 1, M51) Visit Requirements: BEFORE 01-DEC-2026:00:00:00 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 21] Visit: 17 (Visit 2, M51) Visit Requirements: AFTER 16 BY 20 D TO 70 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 22] Visit: 18 (Visit 3, M51) Visit Requirements: AFTER 17 BY 20 D TO 90 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 23] Visit: 19 (Visit 4, M51) Visit Requirements: AFTER 18 BY 20 D TO 90 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 24] Visit: 20 (Visit 5, M51) Visit Requirements: AFTER 19 BY 20 D TO 70 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 25] Visit: 21 (Visit 6, M51) Visit Requirements: AFTER 20 BY 25 D TO 70 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 26] Visit: 22 (Visit 7, M51) Visit Requirements: AFTER 21 BY 20 D TO 120 D 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-51 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=SPARS50, NSAMP=13 1 DEF PATTERN 1 1 CUM (2411.751 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-51 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM M-51 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 18419( 2) - 19-Aug-2026 10:45:14 - [ 27] Summary Form for Proposal 18419 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=12, NSAMP=13, SAMP-SEQ=SPARS25, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 100 D TO 120 D, AFTER 01 BY 170 D TO 220 D, AFTER 01 BY 20 D TO 40 D, AFTER 01 BY 300 D TO 365 D, AFTER 06 BY 5 D TO 30 D, AFTER 07 BY 20 D TO 110 D, AFTER 08 BY 20 D TO 110 D, AFTER 09 BY 20 D TO 110 D, AFTER 11 BY 5 D TO 30 D, AFTER 12 BY 20 D TO 110 D, AFTER 13 BY 20 D TO 110 D, AFTER 14 BY 20 D TO 110 D, AFTER 16 BY 20 D TO 70 D, AFTER 17 BY 20 D TO 90 D, AFTER 18 BY 20 D TO 90 D, AFTER 19 BY 20 D TO 70 D, AFTER 20 BY 25 D TO 70 D, AFTER 21 BY 20 D TO 120 D, BEFORE 01-DEC-2026:00:00:00, BEFORE 31-DEC-2026:00:00:00, PATTERN 1 1, PATTERN 1 1-2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CEN-A-F1, CEN-A-F2, M-51, NGC4258-INNER ------------------------------------------------------------------------------------------------------------------------------------