18366( 3) - 28-Aug-2026 10:42:52 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18366 Version: 3 Check-in Time: 28-Aug-2026 10:42:52 STScI Edit Number: 0 Title An extraordinary dusty Einstein ring at z = 2.95 ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Kevin Huffenberger Texas A & M University Y CoI: Dr. Andrew Baker Rutgers the State University of New Jersey N CoI: Aaron Hughes Texas A & M University N CoI: Dr. John P. Hughes Rutgers the State University of New Jersey N CoI: Matt Hilton University of Witwatersrand N CoI: Dr. Cristian Vargas Texas A & M University N ------------------------------------------------------------------------------------ Abstract We propose a joint HST-JWST program to conduct a multi-wavelength analysis of ACT-S J0732.1+1709, an extraordinary 4"-radius, group-scale Einstein ring at z = 2.95. Discovered as one of the brightest high-redshift sub-mm galaxies, this "cosmic telescope" provides strong magnification (>10), allowing us to resolve the starbursting galaxy at the sub-100 pc scales typically inaccessible at cosmic noon. We will use HST/WFC3 to map unobscured rest-frame UV star formation and JWST/NIRCam to trace the mature stellar backbone in the rest-frame optical. This will reveal if the system is a coherent disk or a complex merger. High-resolution imaging is a prerequisite to identify multiply-imaged knots and the morphology of the lensing group. Combining these data with existing ALMA CO and dust continuum data, we will map star formation efficiency and gas-to-stellar mass ratios. We will also test the IRX-beta relationship at sub-kpc scales and locate intense dust obscuration. We request HST (F606W, F814W) and JWST (F150W, F444W) imaging. To mitigate a nearby bright interloper, we utilize specific dither patterns and roll angles to manage diffraction spikes and saturation. This program provides the essential high-resolution priors needed to resolve the baryon cycle in a system at z = 3. ------------------------------------------------------------------------------------ Observations Description ------------------------ To model the source flux density, we have used a dusty CIGALE SED model (from [23] and consistent with Herschel dusty z ~ 3 galaxies) to translate the mm-wavelength flux density to the HST bands. For the total ring, in F606W we estimate an average flux density of 6.4 * 10^-7 Jy, and in F814 we estimate 2.0 * 10^-6 Jy. For the solid angle of the Einstein ring, we estimate a 4" radius and a 1" thickness, with a filling factor of f = 0.25, characteristic of a DSFG, for an effective solid angle of 6.3 arcsec^2 . Thus the typical surface brightnesses in the two HST bands are 1.0 * 10^-7 Jy arcsec^-2 and 3.2 * 10^-7 18366( 3) - 28-Aug-2026 10:42:52 - [ 2] Jy arcsec^-2 . According to the WFC3 Exposure Time Calculator, under typical conditions and 50 minutes of visibility per orbit, in a typical 0.4"-radius region, six orbits with F606W will yield S/N of 11.3 and six orbits with F814W will yield S/N of 19.3. Since our SED is uncertain in the rest-frame UV, these S/N estimates give us some cushion if the brightness is lower than expected. On the other hand, if the galaxy is less dusty than our model, the rest frame UV emission will be less obscured and brighter. Here is the reasoning for the proposed observations. Nearby star--- The bright star nearby, V~16, will saturate F606W band in about ~18 s. Although exposures this short are possible, the readout overhead is severe, so we have to accept some bloom from the saturated star. A rough computation indicates that the radius of the nearby star bloom will match the radius where the diffraction spikes fall below the background, at 2"-3", at about 600s. I keep all exposures shorter than that. Roll angles--- The available roll angles are roughly 255-332 deg for this target. Unfortunately this directs the CCD columns and thus the bloom from the saturated star toward the Einstein ring. Diffraction spikes are +/- 45 deg from the bloom. We get 12 orbits, so we have chosen 12 visits, with orientation angles to cover the full range. This lets us rotate through almost but not quite 90 degrees, and will distribute the bloom and diffraction spikes differently in each visit of the telescope. Readout times--- The main decision is full frame images (the pair of the UVIS1/UVIS2 CCDs, each 2048x4096) versus sub array images. The onboard buffer can hold two full frame images. The buffer can be dumped while the telescope is exposing if nothing else is happening. Subarrays imaging has better charge transfer efficiency and long exposures have better charge transfer efficiency. Subarray images have shorter readout time, so short exposures with less saturation are more efficient. Short exposures need to be "flashed" which improves CTE at the cost of photon shot noise. The readout times are roughly: 512x512 (20"x20") subarray: 50 s 4096x4096 (160"x160") full frame: 115 s These sizes compare to the ~8"-10" diameter of the Einstein ring. Also, we don't know the redshift of the lens, but the photo-z is z=0.7 +/- 0.3. At 0.7, 10" is about 70-75 kpc, so the smallest subarray covers the Einstein ring, but not very far around the group core, so we need large frames to see the lensing group. Observing sequence per visit--- * 512x512 exposure at F606W repeated x 2 for 275 s each * 512x512 exposure at F814W repeated x 2 for 275 s each 18366( 3) - 28-Aug-2026 10:42:52 - [ 3] * Slight repointing * Full frame exposure at F606W for 567 s * Buffer dump #1 during that exposure * Full frame exposure at F814W for 567 s, readout during occultation * Buffer dump #2 also during Earth occultation Such a sequence gets us shorter exposures in the Einstein Ring for half the time, and the broader field half the time, which covers the lensing group. An alternative is to just do the longer full frame exposures repeatedly. This yields almost the same total time on target overall, but you sacrifice the shorter exposures in the Einstein ring area for 2x deeper coverage in the broader field. Outside the Einstein ring where we are just seeing the lensing group, so we should not need such deep coverage, and the adopted plan with the short exposures helps deal with saturation in the nearby star. ------------------------------------------------------------------------------------ 18366( 3) - 28-Aug-2026 10:42:52 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ACT-S-J0732. GALAXY, EINSTEIN RING, RA=07H32M9.2650S, J2000 26.40 mag arcsec^-2 1+1709 GRAVITATIONAL LENS, DEC=+17D09'43.09" HIGH REDSHIFT GALAXY Reference Frame: ICRS Extended: YES Comments: Estimated surface brightness for F606W. Source should be quite red, and brighter in F814W. ------------------------------------------------------------------------------------------------------------------------------------ 18366( 3) - 28-Aug-2026 10:42:52 - [ 5] Visit: 01 Visit Requirements: ORIENT 290D TO 292 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0, 0 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.357, 4.815 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 6] Visit: 02 Visit Requirements: ORIENT 293D TO 295 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.092, 0.098 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.536, 7.222 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 7] Visit: 03 Visit Requirements: ORIENT 296D TO 298 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.185, 0.197 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.714, 9.630 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 8] Visit: 04 Visit Requirements: ORIENT 299D TO 301 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.277, 0.295 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.357, 4.815 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 9] Visit: 05 Visit Requirements: ORIENT 302D TO 304 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.369, 0.394 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.536, 7.222 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 10] Visit: 06 Visit Requirements: ORIENT 305D TO 307 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.462, 0.492 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.714, 9.630 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 11] Visit: 07 Visit Requirements: ORIENT 307D TO 309 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.554, 0.591 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.357, 4.815 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 12] Visit: 08 Visit Requirements: ORIENT 310D TO 312 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.646, 0.689 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.536, 7.222 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 13] Visit: 09 Visit Requirements: ORIENT 313D TO 315 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.739, 0.788 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.714, 9.630 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 14] Visit: 10 Visit Requirements: ORIENT 316D TO 318 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.831, 0.886 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.357, 4.815 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 15] Visit: 11 Visit Requirements: ORIENT 319D TO 321 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 0.923, 0.985 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.536, 7.222 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 16] Visit: 12 Visit Requirements: ORIENT 322D TO 324 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 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F606W FLASH=10 2 277 S (554 POS TARG 1.016, 1.083 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ACT-S-J0732 WFC3/UVI ACCUM UVIS F606W 1 587 S (587 POS TARG 0.714, 9.630 .1+1709 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ACT-S-J0732 WFC3/UVI ACCUM UVIS2-M51 F814W FLASH=14 2 276 S (552 SAME POS AS 1 .1+1709 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ACT-S-J0732 WFC3/UVI ACCUM UVIS F814W FLASH=5 1 587 S (587 SAME POS AS 2 .1+1709 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 1 WFC3/UVI ACCUM UVIS2-M5 F606W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 2 WFC3/UVI ACCUM UVIS F606W none none none none 1 N/A S ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 1 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 3 WFC3/UVI ACCUM UVIS2-M5 F814W none none 2 none 1 N/A S 12C-SUB ACT-S-J0732.1+1709 4 WFC3/UVI ACCUM UVIS F814W none none none none 1 N/A S 18366( 3) - 28-Aug-2026 10:42:52 - [ 17] Summary Form for Proposal 18366 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS, UVIS2-M512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, FLASH=14, FLASH=5 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 290D TO 292 D, ORIENT 293D TO 295 D, ORIENT 296D TO 298 D, ORIENT 299D TO 301 D, ORIENT 302D TO 304 D, ORIENT 305D TO 307 D, ORIENT 307D TO 309 D, ORIENT 310D TO 312 D, ORIENT 313D TO 315 D, ORIENT 316D TO 318 D, ORIENT 319D TO 321 D, ORIENT 322D TO 324 D, POS TARG 0, 0, POS TARG 0.092, 0.098, POS TARG 0.185, 0.197, POS TARG 0.277, 0.295, POS TARG 0.357, 4.815, POS TARG 0.369, 0.394, POS TARG 0.462, 0.492, POS TARG 0.536, 7.222, POS TARG 0.554, 0.591, POS TARG 0.646, 0.689, POS TARG 0.714, 9.630, POS TARG 0.739, 0.788, POS TARG 0.831, 0.886, POS TARG 0.923, 0.985, POS TARG 1.016, 1.083, SAME POS AS 1, SAME POS AS 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ACT-S-J0732.1+1709 ------------------------------------------------------------------------------------------------------------------------------------