18384( 3) - 19-Aug-2026 15:57:20 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18384 Version: 3 Check-in Time: 19-Aug-2026 15:57:20 STScI Edit Number: 0 Title MUSYC: a Medium Uv deep Survey of Young massive Clusters in the Magellanic Clouds ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Emanuele Dalessandro INAF - Osservatorio di Astrofisica e Y Scienza dello Spazio CoI: Dr. Nate Bastian Donostia International Physics Center N CoI: Dr. Santi Cassisi INAF - Osservatorio Astronomico d'Abruzzo N CoI: Dr. Mario Cadelano Universita di Bologna N CoI: Dr. Alessandro Della Croce Indiana University System N CoI: Msr. Greta Ettorre Universita di Bologna N CoI: Dr. Sebastian Kamann Liverpool John Moores University N CoI: Mrs. Silvia Leanza Universita di Bologna N CoI: Dr. Silvia Martocchia CNRS, Laboratoire d'Astrophysique de N Marseille CoI: Dr. Florian Niederhofer Leibniz-Institut für Astrophysik Potsdam N (AIP) CoI: Dr. Elena Sabbi International Space Science Institute N (ISSI) CoI: Dr. Maurizio Salaris Liverpool John Moores University N CoI: Dr. Sara Saracino INAF - Osservatorio Astrofisico di Arcetri N CoI: Dr. Enrico Vesperini Indiana University System N CoI: Ella Anne Werre Michigan State University N CoI: Prof. Carmela Lardo Universita di Bologna N ------------------------------------------------------------------------------------ Abstract Young massive clusters (YMCs) play a central role in many key research areas ranging from star and cluster formation to stellar evolution. However, their full potential as astrophysical benchmarks is admittedly hampered by the lack of deep UV observations. Here we aim at filling this gap by performing MUSYC, the first deep UV survey of a representative sample of five YMCs younger than ~1.5 Gyr in the Magellanic Clouds. The requested data are a gold mine for a large number of interesting applications. Here we focus on the following science cases. The first one is the search for multiple populations (MPs) with different light-element abundances along the lower main sequence of YMCs by using UV nitrogen-sensitive filters. This analysis will finally show whether MPs are common to all massive clusters (irrespective of their age), thus addressing one of the most important open questions in stellar population studies and enabling the definition of a complete picture about how MP properties evolve across the cosmic time. Secondly, we will explore the nature and origin of the recently identified UV-dim stars, which have been suggested to be fast-rotators with circumstellar disks. This study would thus have a large impact on our understanding of the interplay between stellar rotation, mass-loss and disk formation, with direct implications on stellar evolution models. Finally, the UV sensitivity of the requested data and the large temporal baseline 18384( 3) - 19-Aug-2026 15:57:20 - [ 2] with archival HST images will enable the first complete and homogeneous characterization of exotic objects in YMCs and the derivation of accurate proper motions for detailed internal and global kinematic analysis. ------------------------------------------------------------------------------------ Observations Description ------------------------ Deep WFC3/UVIS observations are requested to observe five young massive clusters in the Magellanic Clouds. For all clusters, we will adopt the same observational strategy. For each cluster 8 orbits will be dedicated to observations with the F343N filter (1 image per orbit), two orbits to obtain 6 images with F438W and two orbits to obtain 6 images with F275W. For NGC1866 we will not acquire F275W images. Observations are split in 4 Visits containing 3 orbits each. For each cluster the first 2 Visits include 3 orbits to get F343N images. The last 2 include 1 orbit to acquire images for each requested filter. The UVIS-CENTER aperture and a WFC3-UVIS-GAP-LINE dither pattern with 3 steps and standard spacing are adopted for all filters. ------------------------------------------------------------------------------------ 18384( 3) - 19-Aug-2026 15:57:20 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-1831 STELLAR CLUSTER, RA=05H06M16.1200S, J2000 V = 11.18 GLOBULAR CLUSTER DEC=-64D55'6.90" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1987 STELLAR CLUSTER, RA=05H27M16.9400S, J2000 V = 11 GLOBULAR CLUSTER DEC=-70D44'14.16" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-411 STELLAR CLUSTER, RA=01H07M55.6400S, J2000 V = 12.1 GLOBULAR CLUSTER DEC=-71D46'3.10" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC-1846 STELLAR CLUSTER, RA=05H07M34.9000S, J2000 V = 11.31 GLOBULAR CLUSTER DEC=-67D27'32.45" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC-1866 STELLAR CLUSTER, RA=05H13M38.9200S, J2000 V = 12 GLOBULAR CLUSTER DEC=-65D27'52.75" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 18384( 3) - 19-Aug-2026 15:57:20 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 2.414 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.759 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 18384( 3) - 19-Aug-2026 15:57:20 - [ 5] Visit: 01 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 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2653 S PATTERN 2 1 S ER (7959 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 6] Visit: 02 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 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2653 S PATTERN 2 1 S ER (7959 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 7] Visit: 03 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 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 798 S PATTERN 2 1 S ER (2394 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 793 S PATTERN 2 2 S ER (2379 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2653 S S ER (2653 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1831 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 8] Visit: 04 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 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 798 S PATTERN 2 1 S ER (2394 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 793 S PATTERN 2 2 S ER (2379 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1831 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2645 S S ER (2645 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1831 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1831 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1831 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 9] Visit: 05 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 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S PATTERN 2 1 S ER (8130 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 10] Visit: 06 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 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S PATTERN 2 1 S ER (8130 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 11] Visit: 07 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 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 818 S PATTERN 2 1 S ER (2454 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 812 S PATTERN 2 2 S ER (2436 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S S ER (2710 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1987 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 12] Visit: 08 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 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 818 S PATTERN 2 1 S ER (2454 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 812 S PATTERN 2 2 S ER (2436 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1987 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S S ER (2710 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1987 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1987 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1987 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 13] Visit: 09 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 NGC-411 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S PATTERN 2 1 S ER (8130 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 14] Visit: 10 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 NGC-411 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S PATTERN 2 1 S ER (8130 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 15] Visit: 11 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 NGC-411 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 818 S PATTERN 2 1 S ER (2454 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-411 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 812 S PATTERN 2 2 S ER (2436 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-411 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S S ER (2710 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-411 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 16] Visit: 12 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 NGC-411 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 818 S PATTERN 2 1 S ER (2454 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-411 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 812 S PATTERN 2 2 S ER (2436 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-411 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2710 S S ER (2710 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-411 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-411 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-411 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 17] Visit: 13 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 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S PATTERN 2 1 S ER (8043 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 18] Visit: 14 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 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S PATTERN 2 1 S ER (8043 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 19] Visit: 15 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 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 808 S PATTERN 2 1 S ER (2424 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 802 S PATTERN 2 2 S ER (2406 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2680 S S ER (2680 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1846 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 20] Visit: 16 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 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=20 1 808 S PATTERN 2 1 S ER (2424 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 802 S PATTERN 2 2 S ER (2406 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-1846 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2680 S S ER (2680 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 1 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 2 none none none 1 N/A S TER NGC-1846 1 WFC3/UVI ACCUM UVIS-CEN F275W 3 none none none 1 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER NGC-1846 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER NGC-1846 3 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 21] Visit: 17 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 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S PATTERN 2 1 S ER (8043 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 22] Visit: 18 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 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S PATTERN 2 1 S ER (8043 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 1 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 2 none none none 2 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F343N 3 none none none 3 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 23] Visit: 19 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 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 810 S PATTERN 2 1 S ER (2430 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S S ER (2681 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 1 N/A S TER NGC-1866 2 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 2 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 24] Visit: 20 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 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 810 S PATTERN 2 1 S ER (2430 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-1866 WFC3/UVI ACCUM UVIS-CENT F343N FLASH=12 1 2681 S S ER (2681 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 1 N/A S TER NGC-1866 1 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 1 N/A S TER NGC-1866 2 WFC3/UVI ACCUM UVIS-CEN F343N none none none none 2 N/A S TER 18384( 3) - 19-Aug-2026 15:57:20 - [ 25] Summary Form for Proposal 18384 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=12, FLASH=20 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1, PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F343N, F438W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC-1831, NGC-1846, NGC-1866, NGC-1987, NGC-411 ------------------------------------------------------------------------------------------------------------------------------------