18005( 5) - 16-Jan-2026 17:14:12 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18005 Version: 5 Check-in Time: 16-Jan-2026 17:14:12 STScI Edit Number: 1 Title 2014 WC510: A second trans-Neptunian triple? ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Benjamin Proudfoot University of Central Florida Board of Y Trustees CoI: Dr. Will M. Grundy Lowell Observatory N CoI: Dr. Audrey Thirouin Lowell Observatory N ------------------------------------------------------------------------------------ Abstract Small planetesimals in the trans-Neptunian region are thought to be formed as the result of gravitational collapse triggered by the streaming instability mechanism. Simulations of such gravitational collapses commonly produce hierarchical triple systems (and other higher multiples), suggesting that they may be common in the trans-Neptunian region. However, to date, only one hierarchical triple has been found, suggesting that either triples are rare or telescopes have not yet reached the necessary resolution to resolve them. Recent HST observations have revealed that 2014 WC510, previously seen to be a closely separated binary, could have a more distant third companion. Alternatively, the system may be a wide binary that happens to be in an edge-on orbit. To determine if WC510 is the Solar System's second confirmed hierarchical triple, we propose a simple 6 orbit program to recover the orbit of the newly discovered distant companion. This provides a sensitive test of the streaming instability formation of planetesimals. Even if not a triple system, our program will precisely measure WC510's mass, providing one of the most precisely known densities in its size range. There is also potential to predict mutual events, which can provide a powerful tool to study WC510 in exquisite detail. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our observations call for 6 single-orbit visits to image the 2014 WC510 system using the WFC3/UVIS instrument. During each visit, images will be acquired using the UVIS2-C512C-SUB aperture, paired with the F350LP filter to optimize astrometric precision. At the end of each visit, two full-frame UVIS2 images will be acquired which provides the data significant legacy value for precise absolute astrometric studies. Exposure times for all images are chosen to optimize SNR and schedulability, with 8 dithered images taken during each visit. This allows us to remain robust to unlucky cosmic ray hits. Scheduling of observations is important to the goals of our program. Recovery of binary is most efficiently accomplished by precisely timed follow-up observations. Our program begins with three "anchor" observations, which should detect the binary system at least two times. These should occur as early as possible in the Cycle and be spaced 4-8 days apart. Based on these initial detections, alongside the discovery observation, precise times for follow-up can be calculated. Hence, Visits 4-6 are placed "On hold" until after 18005( 5) - 16-Jan-2026 17:14:12 - [ 2] acquisition and analysis of Visits 1-3. Then, each further visit will be updated with "betweens" to efficiently recover the binary orbit. The timing windows input into the Phase II are somewhat flexible, and can be changed if necessary. If more observing windows are needed, we can provide them, although we will usually provide our "optimal" windows. Once preliminary scheduling windows are identified, we will check for bright nearby stars that could degrade image quality. ------------------------------------------------------------------------------------ 18005( 5) - 16-Jan-2026 17:14:12 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 TARGET NAME: WC510 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: ASTEROID TNO trinary? ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 TARGET POSITION LEVEL 2 TYPE=ASTEROID, A=39.63878743404138, E=0.2551217183892524, I=19.54803566488891 , O=194.5694855695911, W=288.8516732889418, M=336.7155725065204, EQUINOX=J2000, EPOCH=29-SEP-2015:00:00:00, EpochTimeScale=TDB ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 WINDOWS ------------------------------------------------------------------------------------------------------------------------------------ DATA COMMENTS V = 23 Ephemeris Center: EARTH Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 18005( 5) - 16-Jan-2026 17:14:12 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 18005( 5) - 16-Jan-2026 17:14:12 - [ 5] Visit: 01 (Anchor 1) Visit Requirements: SCHED 100%; BEFORE 15-NOV-2025:00:00:00 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 6] Visit: 02 (Anchor 2) Visit Requirements: SCHED 100%; AFTER 01 BY 4 D TO 8 D On Hold Comments: Additional Comments: Should be 4-8 days after Visit 1. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 7] Visit: 03 (Anchor 3) Visit Requirements: SCHED 100%; AFTER 02 BY 4 D TO 8 D On Hold Comments: Additional Comments: Should be 4-8 days after Visit 2. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 8] Visit: 04 (Follow-up 1) Visit Requirements: SCHED 100%; BETWEEN 21-DEC-2025:00:00:00 AND 25-DEC-2025:00:00:00 On Hold Comments: Additional Comments: Based on the first three visits, we have determined a range of times when the system is ideal to observe. The ideal observation date is 2025-12-23 00:00 +/- 2 days. If this timing is not possible, we can rerun our analysis and find alternate times. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 9] Visit: 05 (Follow-up 2) Visit Requirements: SCHED 100%; BETWEEN 28-DEC-2025:12:00:00 AND 01-JAN-2026:12:00:00 On Hold Comments: Additional Comments: Based on the first three visits, we have determined a range of times when the system is ideal to observe. The ideal observation date is 2025-12-30 12:00 +/- 2 days. If this timing is not possible, we can rerun our analysis and find alternate times. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 10] Visit: 06 (Follow-up 3) Visit Requirements: SCHED 100%; ON HOLD On Hold Comments: Based on the discovery observation (taken as part of program 17524) and the first five visits, optimal scheduling opportunities will be calculated and provided ASAP after Visits 1-5 are taken. These will be provided as "betweens" that last a few days. Additional Comments: On hold will be removed and replaced with "betweens" after acquisition and analysis of Visits 1-5. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 11] Visit: 12 (Follow-up 4) Visit Requirements: SCHED 100%; ON HOLD On Hold Comments: Based on the discovery observation (taken as part of program 17524) and the previous visits, optimal scheduling opportunities will be calculated and provided ASAP after Visits 1-5 are taken. These will be provided as "betweens" that last a few days. Backup opportunities will be available. Additional Comments: Repeat of failed visit 02. Unfortunately, due to the failure of visit 03, less information is available about the orbit period of our target than originally planned. To remedy this, we are getting another "anchor" pair using visits 04 and 05, which should enable scheduling for the final follow-up visits (06 and 12). Scheduling for this visit will be placed on hold, as with visit 06. 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 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (800 SEQ 1-3 NON-INT; PATTERN S 2C-SUB S) 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 WC510 WFC3/UVI ACCUM UVIS2-C51 F350LP FLASH=1 1 200 S (400 PATTERN 2 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WC510 WFC3/UVI ACCUM UVIS2 F350LP FLASH=1 1 200 S (400 PATTERN 2 3 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 | ------------------------------------------------------------------------------------------------------------------------------------ WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 3 none none none 1 N/A S 12C-SUB WC510 1 WFC3/UVI ACCUM UVIS2-C5 F350LP 4 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 1 none none none 1 N/A S 12C-SUB WC510 2 WFC3/UVI ACCUM UVIS2-C5 F350LP 2 none none none 1 N/A S 12C-SUB WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 1 none none none 1 N/A S WC510 3 WFC3/UVI ACCUM UVIS2 F350LP 2 none none none 1 N/A S 18005( 5) - 16-Jan-2026 17:14:12 - [ 12] Summary Form for Proposal 18005 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2, UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=1 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 4 D TO 8 D, AFTER 02 BY 4 D TO 8 D, BEFORE 15-NOV-2025:00:00:00, BETWEEN 21-DEC-2025:00:00:00 AND 25-DEC-2025:00:00:00, BETWEEN 28-DEC-2025:12:00:00 AND 01-JAN-2026:12:00:00, ON HOLD , PATTERN 1 1, PATTERN 2 2, PATTERN 2 3, SCHED 100%, SEQ 1-3 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names WC510 ------------------------------------------------------------------------------------------------------------------------------------