18388( 3) - 18-Aug-2026 18:48:17 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18388 Version: 3 Check-in Time: 18-Aug-2026 18:48:17 STScI Edit Number: 0 Title Resolving the Connection between LFBOTs and Star Formation ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Daniel Perley Liverpool John Moores University Y CoI: Anna Yen Qin Ho Cornell University N CoI: Dr. Lin Yan California Institute of Technology N CoI: Prof. Andrew James Levan Radboud University Nijmegen N CoI: Dr. Steve Schulze Weizmann Institute of Science N CoI: Dr. Ragnhild Lunnan Stockholm University N CoI: Cassie Sevilla Cornell University N CoI: Gokul Prem Srinivasaragavan University of Maryland N CoI: Jacob Wise Liverpool John Moores University N CoI: Ms. Zoe McGrath Liverpool John Moores University N ------------------------------------------------------------------------------------ Abstract Luminous Fast Blue Optical Transients (LFBOTs) are a class of rare, exotic transients likely produced by the rapid accretion of material onto a black hole. Their properties indicate that the mass scale of the accreted object, the black hole, or both are quite different to what is known from other populations: they may result from the formation of very massive (>50 solar mass) stellar black holes following core-collapse or the disruption of stars by intermediate-mass (10^4 solar mass) black holes. The uncertainty in their progenitors arises in large part because their hosts are too distant to usefully resolve from the ground. HST observations have played essential roles in establishing the age and mass of various transient populations, by identifying (or ruling out) associations with young star-forming regions and statistically associating the locations of the transients with the distribution of UV light across the host more broadly. The sample of LFBOTs is now sufficiently large to deploy these methods on this population. We propose to use HST to study the local environments of the full sample of confirmed LFBOTs to test different models of their origins and constrain the mass scales of the progenitor star and black hole. By testing a potential production channel for large black holes - or alternatively, unveiling a population of previously hidden intermediate mass black holes - the results will have important implications for our understanding of the properties and evolution of black holes in the universe more generally. ------------------------------------------------------------------------------------ Observations Description ------------------------ The goal of the program is to obtain resolved imaging (in the rest-frame near-UV where possible) of a set of LFBOT host galaxies to ascertain whether the transients hosted within these galaxies lie in or near star-forming regions. The galaxies are distant and span a wide range of surface brightnesses, and range between redshift 0.03 to 0.34. Where possible, our goal is to map the position of the transient (available from ground-based optical imaging and/or radio interferometry) onto the host to approximately 0.1 arcsec 18388( 3) - 18-Aug-2026 18:48:17 - [ 2] relative astrometric accuracy. For brighter galaxies (visits 1, 2, 4, 5, 8) we use a single orbit with a standard UVIS 3-point line dither in either F336W or F390W with the detector subarrayed (C1K1C-SUB) to avoid a buffer delay. This is followed by a shorter observation using 2-point line dither in F350LP (with no subarray using the C1K1C-CTE aperture), primarily for astrometric purposes (but also to characterize the optical light distribution of the host). For somewhat fainter galaxies (visits 3, 6, 7, 9, 10), we observe for 2 orbits (or in one case 3 orbits) using F336W or F390W and use a 2-point line dither within each orbit, with additional small offsets applied between orbits. The last orbit includes 2-point line dither in F350LP, with the F336W/F390W observations during that orbit shortened accordingly. As with the brighter galaxies, the F336W/F390W observations are subarrayed but the F350LP observations are not. For the faintest galaxies (visits 11, 12, 13), we observe only in long-pass filters, using a 4-point dither spanning two orbits (F200LP), plus one additional orbit using a 4-point dither in F350LP. We use the flash option as needed to ensure at least 20 e-/pix as recommended by the APT. ------------------------------------------------------------------------------------ 18388( 3) - 18-Aug-2026 18:48:17 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CSS161010 STAR, SUPERNOVA RA=04H58M34.4000S, J2000 V = 21.4 DEC=-08D18'3.90" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2018LUG STAR, SUPERNOVA RA=02H00M15.1900S, J2000 V = 21.7 DEC=+16D47'57.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2020MRF STAR, SUPERNOVA RA=15H47M54.1700S, J2000 V = 24.5 DEC=+44D39'7.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 4 AT2022TSD STAR, SUPERNOVA RA=03H20M10.8700S, J2000 V = 21.4 DEC=+08D44'55.90" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 5 AT2022ABFC STAR, SUPERNOVA RA=04H51M19.2000S, J2000 V = 19.1 DEC=-26D58'41.60" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 6 AT2023HKW STAR, SUPERNOVA RA=10H42M17.7500S, J2000 V = 21.8 DEC=+52D29'19.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 7 AT2023VTH STAR, SUPERNOVA RA=17H56M34.4000S, J2000 V = 22.1 DEC=+08D02'37.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 8 AT2024QFM STAR, SUPERNOVA RA=23H21M23.4600S, J2000 V = 22.0 DEC=+11D56'32.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 9 AT2024AEHP STAR, SUPERNOVA RA=08H21M7.4700S, J2000 V = 21.7 DEC=+28D44'22.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 10 AT2026DBL STAR, SUPERNOVA RA=09H01M17.3700S, J2000 V = 21.0 DEC=+18D36'7.80" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 11 AT2020XND STAR, SUPERNOVA RA=22H20M2.0300S, J2000 V = 25.6 DEC=-02D50'25.30" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 12 AT2023FHN STAR, SUPERNOVA RA=10H08M3.8200S, J2000 V = 23.9 DEC=+21D04'26.90" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 18388( 3) - 18-Aug-2026 18:48:17 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 13 AT2024WPP STAR, SUPERNOVA RA=02H42M5.5000S, J2000 V = 22.0 DEC=-16D57'22.90" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 18388( 3) - 18-Aug-2026 18:48:17 - [ 5] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 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 ------------------------------------------------------------------------------------------------------------------------------------ 18388( 3) - 18-Aug-2026 18:48:17 - [ 6] Visit: 01 (CSS161010) 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 CSS161010 WFC3/UVI ACCUM UVIS2-C1K F336W FLASH=15 1 620 S PATTERN 3 1 S 1C-SUB (1860 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CSS161010 WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=3 1 180 S (360 PATTERN 2 2 S 1C-CTE 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 | ------------------------------------------------------------------------------------------------------------------------------------ CSS161010 1 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none none 1 N/A S K1C-SUB CSS161010 1 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none none 1 N/A S K1C-SUB CSS161010 1 WFC3/UVI ACCUM UVIS2-C1 F336W 3 none none none 1 N/A S K1C-SUB CSS161010 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 N/A S K1C-CTE CSS161010 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 7] Visit: 02 (AT2018lug) 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 AT2018LUG WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=11 1 620 S PATTERN 3 1 S 1C-SUB see below (1866 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2018LUG WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=3 1 180 S PATTERN 2 2 S 1C-CTE see below (364 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2018LUG 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 622.0 S S K1C-SUB AT2018LUG 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 622.0 S S K1C-SUB AT2018LUG 1 WFC3/UVI ACCUM UVIS2-C1 F390W 3 none none none 1 622.0 S S K1C-SUB AT2018LUG 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 182.0 S S K1C-CTE AT2018LUG 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 182.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 8] Visit: 03 (AT2020mrf) 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 AT2020MRF WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=6 1 1250 S PATTERN 2 1 S 1C-SUB see below (2500 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2020MRF WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=6 1 1250 S POS TARG +0.06, -0.07; S 1C-SUB see below PATTERN 2 2 (2500 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2020MRF WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=9 1 980 S POS TARG -0.092, +0.098; S 1C-SUB see below PATTERN 2 3 (1960 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 AT2020MRF WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=5 1 150 S PATTERN 2 4 S 1C-CTE see below (300 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2020MRF 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 1250.0 S S K1C-SUB AT2020MRF 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 1250.0 S S K1C-SUB AT2020MRF 2 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 2 1250.0 S S K1C-SUB AT2020MRF 2 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 2 1250.0 S S K1C-SUB AT2020MRF 3 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 3 980.0 S S K1C-SUB AT2020MRF 3 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 3 980.0 S S K1C-SUB AT2020MRF 4 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 3 150.0 S S K1C-CTE AT2020MRF 4 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 3 150.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 9] Visit: 04 (AT2022tsd) 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 AT2022TSD WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=11 1 620 S PATTERN 3 1 S 1C-SUB see below (1866 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2022TSD WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=3 1 180 S PATTERN 2 2 S 1C-CTE see below (364 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2022TSD 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 622.0 S S K1C-SUB AT2022TSD 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 622.0 S S K1C-SUB AT2022TSD 1 WFC3/UVI ACCUM UVIS2-C1 F390W 3 none none none 1 622.0 S S K1C-SUB AT2022TSD 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 182.0 S S K1C-CTE AT2022TSD 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 182.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 10] Visit: 05 (AT2022abfc) 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 AT2022ABFC WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=11 1 630 S PATTERN 3 1 S 1C-SUB see below (1908 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2022ABFC WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=4 1 160 S PATTERN 2 2 S 1C-CTE see below (332 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2022ABFC 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 636.0 S S K1C-SUB AT2022ABFC 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 636.0 S S K1C-SUB AT2022ABFC 1 WFC3/UVI ACCUM UVIS2-C1 F390W 3 none none none 1 636.0 S S K1C-SUB AT2022ABFC 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 166.0 S S K1C-CTE AT2022ABFC 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 166.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 11] Visit: 06 (AT2023hkw) 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 AT2023HKW WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=6 1 1260 S PATTERN 2 1 S 1C-SUB see below (2520 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2023HKW WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=9 1 980 S POS TARG +0.06, -0.07; S 1C-SUB see below PATTERN 2 2 (1960 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2023HKW WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=4 1 160 S PATTERN 2 3 S 1C-CTE see below (320 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2023HKW 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 1260.0 S S K1C-SUB AT2023HKW 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 1260.0 S S K1C-SUB AT2023HKW 2 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 2 980.0 S S K1C-SUB AT2023HKW 2 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 2 980.0 S S K1C-SUB AT2023HKW 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 2 160.0 S S K1C-CTE AT2023HKW 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 2 160.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 12] Visit: 07 (AT2023vth) 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 AT2023VTH WFC3/UVI ACCUM UVIS2-C1K F336W FLASH=13 1 1240 S PATTERN 2 1 S 1C-SUB see below (2494 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2023VTH WFC3/UVI ACCUM UVIS2-C1K F336W FLASH=14 1 960 S POS TARG +0.06, -0.07; S 1C-SUB see below PATTERN 2 2 (1926 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2023VTH WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=5 1 150 S PATTERN 2 3 S 1C-CTE see below (306 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2023VTH 1 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none none 1 1247.0 S S K1C-SUB AT2023VTH 1 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none none 1 1247.0 S S K1C-SUB AT2023VTH 2 WFC3/UVI ACCUM UVIS2-C1 F336W 1 none none none 2 963.0 S S K1C-SUB AT2023VTH 2 WFC3/UVI ACCUM UVIS2-C1 F336W 2 none none none 2 963.0 S S K1C-SUB AT2023VTH 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 2 153.0 S S K1C-CTE AT2023VTH 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 2 153.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 13] Visit: 08 (AT2024qfm) 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 AT2024QFM WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=11 1 640 S PATTERN 3 1 S 1C-SUB (1920 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2024QFM WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=5 1 150 S (300 PATTERN 2 2 S 1C-CTE 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024QFM 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 N/A S K1C-SUB AT2024QFM 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 N/A S K1C-SUB AT2024QFM 1 WFC3/UVI ACCUM UVIS2-C1 F390W 3 none none none 1 N/A S K1C-SUB AT2024QFM 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 N/A S K1C-CTE AT2024QFM 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 14] Visit: 09 (AT2024aehp) 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 AT2024AEHP WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=11 1 635 S PATTERN 3 1 S 1C-SUB see below (1914 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2024AEHP WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=4 1 160 S PATTERN 2 2 S 1C-CTE see below (326 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024AEHP 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 638.0 S S K1C-SUB AT2024AEHP 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 638.0 S S K1C-SUB AT2024AEHP 1 WFC3/UVI ACCUM UVIS2-C1 F390W 3 none none none 1 638.0 S S K1C-SUB AT2024AEHP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 1 163.0 S S K1C-CTE AT2024AEHP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 1 163.0 S S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 15] Visit: 10 (AT2026dbl) 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 AT2026DBL WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=6 1 1240 S PATTERN 2 1 S 1C-SUB see below (2496 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2026DBL WFC3/UVI ACCUM UVIS2-C1K F390W FLASH=9 1 960 S POS TARG +0.06, -0.07; S 1C-SUB (1920 S) PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 AT2026DBL WFC3/UVI ACCUM UVIS2-C1K F350LP FLASH=5 1 150 S (300 PATTERN 2 3 S 1C-CTE 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2026DBL 1 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 1 1248.0 S S K1C-SUB AT2026DBL 1 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 1 1248.0 S S K1C-SUB AT2026DBL 2 WFC3/UVI ACCUM UVIS2-C1 F390W 1 none none none 2 N/A S K1C-SUB AT2026DBL 2 WFC3/UVI ACCUM UVIS2-C1 F390W 2 none none none 2 N/A S K1C-SUB AT2026DBL 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 2 N/A S K1C-CTE AT2026DBL 3 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 2 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 16] Visit: 11 (AT2020xnd) 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 AT2020XND WFC3/UVI ACCUM UVIS2-C1K F200LP 1 1220 S PATTERN 4 1 S 1C-CTE (4880 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2020XND WFC3/UVI ACCUM UVIS2-C1K F350LP 1 550 S PATTERN 4 2 S 1C-CTE (2200 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2020XND 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 1 none none none 1 N/A S K1C-CTE AT2020XND 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 2 none none none 1 N/A S K1C-CTE AT2020XND 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 3 none none none 2 N/A S K1C-CTE AT2020XND 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 4 none none none 2 N/A S K1C-CTE AT2020XND 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 3 N/A S K1C-CTE AT2020XND 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 3 N/A S K1C-CTE AT2020XND 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 3 none none none 3 N/A S K1C-CTE AT2020XND 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 4 none none none 3 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 17] Visit: 12 (AT2023fhn) 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 AT2023FHN WFC3/UVI ACCUM UVIS2-C1K F200LP 1 1220 S PATTERN 4 1 S 1C-CTE (4880 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2023FHN WFC3/UVI ACCUM UVIS2-C1K F350LP 1 550 S PATTERN 4 2 S 1C-CTE (2200 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2023FHN 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 1 none none none 1 N/A S K1C-CTE AT2023FHN 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 2 none none none 1 N/A S K1C-CTE AT2023FHN 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 3 none none none 2 N/A S K1C-CTE AT2023FHN 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 4 none none none 2 N/A S K1C-CTE AT2023FHN 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 3 N/A S K1C-CTE AT2023FHN 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 3 N/A S K1C-CTE AT2023FHN 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 3 none none none 3 N/A S K1C-CTE AT2023FHN 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 4 none none none 3 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 18] Visit: 13 (AT2024wpp) 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 AT2024WPP WFC3/UVI ACCUM UVIS2-C1K F200LP 1 1220 S PATTERN 4 1 S 1C-CTE (4880 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AT2024WPP WFC3/UVI ACCUM UVIS2-C1K F350LP 1 550 S PATTERN 4 2 S 1C-CTE (2200 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 | ------------------------------------------------------------------------------------------------------------------------------------ AT2024WPP 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 1 none none none 1 N/A S K1C-CTE AT2024WPP 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 2 none none none 1 N/A S K1C-CTE AT2024WPP 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 3 none none none 2 N/A S K1C-CTE AT2024WPP 1 WFC3/UVI ACCUM UVIS2-C1 F200LP 4 none none none 2 N/A S K1C-CTE AT2024WPP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 1 none none none 3 N/A S K1C-CTE AT2024WPP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 2 none none none 3 N/A S K1C-CTE AT2024WPP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 3 none none none 3 N/A S K1C-CTE AT2024WPP 2 WFC3/UVI ACCUM UVIS2-C1 F350LP 4 none none none 3 N/A S K1C-CTE 18388( 3) - 18-Aug-2026 18:48:17 - [ 19] Summary Form for Proposal 18388 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C1K1C-CTE, UVIS2-C1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=11, FLASH=13, FLASH=14, FLASH=15, FLASH=3, FLASH=4, FLASH=5, FLASH=6, FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1, PATTERN 2 2, PATTERN 2 3, PATTERN 2 4, PATTERN 3 1, PATTERN 4 1, PATTERN 4 2, POS TARG +0.06, -0.07, POS TARG -0.092, +0.098 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F200LP, F336W, F350LP, F390W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AT2018LUG, AT2020MRF, AT2020XND, AT2022ABFC, AT2022TSD, AT2023FHN, AT2023HKW, AT2023VTH, AT2024AEHP, AT2024QFM, AT2024WPP, AT2026DBL, CSS161010 ------------------------------------------------------------------------------------------------------------------------------------