18097( 5) - 02-Apr-2026 17:25:20 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18097 Version: 5 Check-in Time: 02-Apr-2026 17:25:20 STScI Edit Number: 0 Title Breaking the mass sheet degeneracy in strong lensing time delay cosmology with a new sample of double source plane lenses. ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Tian Li Portsmouth University/ICG Y CoI: Dr. Thomas E. Collett University of Portsmouth N CoI: Dr. Wolfgang Johannes Rudolf Enzi University of Portsmouth N CoI: Natalie Lines University of Portsmouth N CoI: Dr. Karina Rojas Fachhochschule Nordwestschweiz N CoI: Dr. Raphael Gavazzi CNRS, Laboratoire d'Astrophysique de N Marseille CoI: Dr. Stefan Schuldt Universita di Milano N CoI: Dr. Aymeric Galan Technical University of Munich N CoI: Prof. Claudio Grillo Universita di Milano N CoI: Dr. Alessandro Sonnenfeld Shanghai Jiao Tong University N CoI: Ana Acebron Instituto de Fisica de Cantabria N CoI: Dr. Robert Benton Metcalf Universita di Bologna N CoI: Dr. Leonidas A Moustakas Jet Propulsion Laboratory N CoI: Giovanni Granata Portsmouth University/ICG N CoI: Dr. James William Nightingale Durham University N CoI: Mr. Leon Roman Ecker Ludwig Maximilian Universitat of Munich N CoI: Dr. Conor O'Riordan Max Planck Institute for Astrophysics N ------------------------------------------------------------------------------------ Abstract Despite years of scrutiny, the measurement of H0 from SH0ES is still at 5-sigma tension with early-Universe probes. If the 8% difference is real it implies physics beyond LCDM. It is essential to develop independent methods with sufficient precision and accuracy to confirm or rule out the tension. A number of collaborations used gravitational time delays to measure H0 to 2% precision assuming that the mass density profiles of massive elliptical galaxies are described by a power-law or stars + Navarro Frenk White dark matter halos. However, if the assumption is relaxed under the mass sheet transformation, the precision of H0 from time delays drops to 8%. Strong lenses with two background sources at different redshifts (double source plane lens, DSPL) allow tight constraints on the main degeneracy of the Hubble constant measurement from time-delay cosmography. We have discovered 9 new galaxy-scale candidates from a combination of Euclid lens searches, and we plan to observe them with HST WFC3. HST is the BEST telescope suitable for this science due to its wavelength coverage and resolution. With our new samples, we are able to increase the measurement of H0 from Time Delay lenses from 6-8% to 2-4%. In addition, due to the second ring providing an extra aperture within which the mass is well constrained, DSPLs are better compared to lens systems with a single ring in almost every other science category involving galaxy scale strong lensing. ------------------------------------------------------------------------------------ 18097( 5) - 02-Apr-2026 17:25:20 - [ 2] Observations Description ------------------------ The main goal of the proposed HST program is to obtain high-resolution images of nine double-source-plane strong-lensing systems, allocating two orbits per system. Combined with spectroscopic redshifts and stellar kinematics, these data will enable detailed lens modeling and a decomposition of the stellar and dark-matter mass components. This, in turn, allows us to quantify and break the mass-sheet degeneracy that would persist if the lens were constrained by a single power-law mass profile alone. HST imaging in F475W and F814W maximizes wavelength coverage, and the angular resolution is improved compared with Euclid. The bluer filter enhances the signal from the blue arcs while suppressing shot noise from the red foreground lens galaxy. We will need one full orbit each in F475W and F814W, employing a four-point dither pattern to carry out the proposed measurements. ------------------------------------------------------------------------------------ 18097( 5) - 02-Apr-2026 17:25:20 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 TEAPOTLENS GALAXY, GRAVITATIONAL RA=18H14M22.7160S, J2000 V = 21 LENS DEC=+67D08'16.26" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 DARTBOARD GALAXY, GRAVITATIONAL RA=03H58M15.5160S, J2000 V = 22 LENS DEC=-50D56'48.84" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 AMMONITE GALAXY, GRAVITATIONAL RA=04H04M57.3240S, J2000 V = 21 LENS DEC=-49D22'21.54" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 4 GALILEO GALAXY, GRAVITATIONAL RA=04H26M44.2992S, J2000 V = 22.7 LENS DEC=-48D06'38.70" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 5 EUCLIDDSPL11 GALAXY, GRAVITATIONAL RA=11H59M42.5520S, J2000 V = 22 5943+673249 LENS DEC=+67D42'49.68" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 6 EUCLIDDSPL12 GALAXY, GRAVITATIONAL RA=12H57M18.5520S, J2000 V = 22 5718+640613 LENS DEC=+64D06'13.32" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 7 EUCLIDDSPL23 GALAXY, GRAVITATIONAL RA=23H53M19.4640S, J2000 V = 22 5319-602119 LENS DEC=-60D21'19.80" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 8 EUCLIDDSPL04 GALAXY, GRAVITATIONAL RA=04H44M53.0640S, J2000 V = 22 4453-380845 LENS DEC=-38D08'45.60" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 9 EUCLIDDSPL05 GALAXY, GRAVITATIONAL RA=05H32M33.6240S, J2000 V = 22 3233-371545 LENS DEC=-37D15'45.72" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 18097( 5) - 02-Apr-2026 17:25:20 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18097( 5) - 02-Apr-2026 17:25:20 - [ 5] Visit: 01 (teapot 475) Visit Requirements: 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 TEAPOTLENS WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 575 S PATTERN 1 1 S (2300 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 | ------------------------------------------------------------------------------------------------------------------------------------ TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 6] Visit: 02 (teapot 814) Visit Requirements: 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 TEAPOTLENS WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 575 S PATTERN 1 1 S (2300 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 | ------------------------------------------------------------------------------------------------------------------------------------ TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S TEAPOTLENS 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 7] Visit: 03 (dartboard 475) Visit Requirements: 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 DARTBOARD WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 559 S PATTERN 1 1 S (2236 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 | ------------------------------------------------------------------------------------------------------------------------------------ DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 8] Visit: 04 (dartboard814W) Visit Requirements: 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 DARTBOARD WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 559 S PATTERN 1 1 S (2236 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 | ------------------------------------------------------------------------------------------------------------------------------------ DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 9] Visit: 05 (ammonite 475) Visit Requirements: 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 AMMONITE WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 555 S PATTERN 1 1 S (2220 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 | ------------------------------------------------------------------------------------------------------------------------------------ AMMONITE 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 10] Visit: 06 (ammonite 814W) Visit Requirements: 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 AMMONITE WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 555 S PATTERN 1 1 S (2220 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 | ------------------------------------------------------------------------------------------------------------------------------------ AMMONITE 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S AMMONITE 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 11] Visit: 07 (galileo 475) Visit Requirements: 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 GALILEO WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 555 S PATTERN 1 1 S (2220 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 | ------------------------------------------------------------------------------------------------------------------------------------ GALILEO 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 12] Visit: 08 (galileo 814) Visit Requirements: 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 GALILEO WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 555 S PATTERN 1 1 S (2220 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 | ------------------------------------------------------------------------------------------------------------------------------------ GALILEO 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S GALILEO 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 13] Visit: 09 (DSPL1159+6732 475) Visit Requirements: 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 EUCLIDDSPL1 WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 575 S PATTERN 1 1 15943+67324 S (2300 S) 9 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A 3249 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 14] Visit: 10 (DSPL1159+6732 814) Visit Requirements: 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 EUCLIDDSPL1 WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 575 S PATTERN 1 1 15943+67324 S (2300 S) 9 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A 3249 S EUCLIDDSPL115943+67 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A 3249 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 15] Visit: 11 (DSPL1257+6406 475) Visit Requirements: 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 EUCLIDDSPL1 WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 568 S PATTERN 1 1 25718+64061 S (2272 S) 3 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A 0613 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 16] Visit: 12 (DSPL1257+6406 814) Visit Requirements: 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 EUCLIDDSPL1 WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 568 S PATTERN 1 1 25718+64061 S (2272 S) 3 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A 0613 S EUCLIDDSPL125718+64 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A 0613 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 17] Visit: 13 (DSPL2353-6021 F475) Visit Requirements: 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 EUCLIDDSPL2 WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 568 S PATTERN 1 1 35319-60211 S (2272 S) 9 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A 2119 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 18] Visit: 14 (DSPL2353-6021 F814) Visit Requirements: 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 EUCLIDDSPL2 WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 568 S PATTERN 1 1 35319-60211 S (2272 S) 9 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A 2119 S EUCLIDDSPL235319-60 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A 2119 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 19] Visit: 15 (DSPL0444-3808 F475) Visit Requirements: 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 EUCLIDDSPL0 WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 550 S PATTERN 1 1 44453-38084 S (2200 S) 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A 0845 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 20] Visit: 16 (DSPL0444-3808 F814) Visit Requirements: 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 EUCLIDDSPL0 WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 550 S PATTERN 1 1 44453-38084 S (2200 S) 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A 0845 S EUCLIDDSPL044453-38 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A 0845 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 21] Visit: 17 (DSPL0532-3715 F475) Visit Requirements: 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 EUCLIDDSPL0 WFC3/UVI ACCUM UVIS2 F475W FLASH=9 1 550 S PATTERN 1 1 53233-37154 S (2200 S) 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F475W 1 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F475W 2 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F475W 3 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F475W 4 none none none 1 N/A 1545 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 22] Visit: 18 (DSPL0532-3715 F814) Visit Requirements: 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 EUCLIDDSPL0 WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 550 S PATTERN 1 1 53233-37154 S (2200 S) 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 | ------------------------------------------------------------------------------------------------------------------------------------ EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A 1545 S EUCLIDDSPL053233-37 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A 1545 S 18097( 5) - 02-Apr-2026 17:25:20 - [ 23] Visit: 19 (dartboard814W) Visit Requirements: 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 DARTBOARD WFC3/UVI ACCUM UVIS2 F814W FLASH=8 1 559 S PATTERN 1 1 S (2236 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 | ------------------------------------------------------------------------------------------------------------------------------------ DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S DARTBOARD 1 WFC3/UVI ACCUM UVIS2 F814W 4 none none none 1 N/A S 18097( 5) - 02-Apr-2026 17:25:20 - [ 24] Summary Form for Proposal 18097 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=8, FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AMMONITE, DARTBOARD, EUCLIDDSPL044453-380845, EUCLIDDSPL053233-371545, EUCLIDDSPL115943+673249, EUCLIDDSPL125718+640613, EUCLIDDSPL235319-602119, GALILEO, TEAPOTLENS ------------------------------------------------------------------------------------------------------------------------------------