18093( 5) - 04-Feb-2026 21:19:58 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18093 Version: 5 Check-in Time: 04-Feb-2026 21:19:58 STScI Edit Number: 0 Title Photoevaporating disks in the final evolution phase: Probing Sigma Orionis with HST/WFC3 ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dra. Karina Mauco Instituto de Astronomia - UNAM Y CoI: Mari Liis Aru European Southern Observatory - Germany N CoI: Dra. Silvia M. H. Vicente Institute of Astrophysics and Space N Sciences (IA) - Lisbon CoI: Dr. Massimo Robberto Space Telescope Science Institute N CoI: Dr. Thomas Haworth Queen Mary University of London N CoI: Prof. Stefano Facchini Universita di Milano N CoI: Dr. Anna Miotello European Southern Observatory - Germany N CoI: Dr. Carlo F. Manara European Southern Observatory - Germany N CoI: Dr. Giovanni Rosotti Universita di Milano N CoI: Dr. Andrew Winter Queen Mary University of London N CoI: Dr. Megan Ansdell NASA Headquarters N CoI: Dr. Juan M. Alcala INAF - Osservatorio Astronomico di N Capodimonte CoI: Dr. Giulia Ballabio Imperial College London N ------------------------------------------------------------------------------------ Abstract The evolutionary pathways of protoplanetary disks differ depending on the surrounding environment. Theoretical models and observational evidence point to external photoevaporation by OB stars playing a significant role in the evolution of planet-forming disks in clusters. As the majority of exoplanet we know did form in such environments, it is mandatory to better understand this process. The effect of external photoevaporation is a depletion of the disk outside-in, severely shortening disk lifetimes. Previous studies have focused on analysing externally-induced disk winds in young (<1-2 Myr) star-forming regions and in high radiation fields. Here we aim to target the intermediate age (3-5 Myr) and milder radiation field Sigma Orionis cluster, a region with disks that have never been imaged in visible light with HST or other high spatial resolution instruments before. We propose, for the first time, to resolve the final stages of disk dissipation caused by photoevaporation with the UVIS camera of HST/WFC3 in three narrow-band filters, tuned to reveal the cocoon around the targets, tell-tale proxy of ongoing external photoevaporation from the massive stars at the center of the cluster. We will thus measure the size of the ionization fronts, and infer the mass loss rates in the winds. These observations will allow us to determine key diagnostics necessary to constrain external photoevaporation models at a later stage of disk evolution and at lower incident radiation than previously observed. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan to observe with HST four fields which include the best ten candidates for detecting a proplyd structure based on their optical emission lines. In the 18093( 5) - 04-Feb-2026 21:19:58 - [ 2] same fields, several other targets known to have disks through ALMA detections (Ansdell et al. 2017) are included. Therefore, we will be able to detect additional proplyds, if any. This sample will cover a range of G0 ~10^3 - 10^5, allowing us to test external photoevaporation models in a wide range of (relatively low) G0, at ages older than previously studied. Each field will be observed with WFC3/UVIS using three narrow-band filters, F656N (Halpha), F631N ([OI]), and F658N ([NII]). These are chosen to spatially resolve ionization fronts and proplyd tails. WFC3/UVIS provides the best sampling, largest FoV, and has the required narrow-band filters. Using WFC3 instead of ACS leads to a better spatial resolution, thanks to the better pixel size, to higher sensitivity, and gives the possibility to use the best narrow band filters for our observations. The HST diffraction limit in Halpha is ~70 mas, which means we will be able to spatially resolve structures as small as ~30 AU for a distance of ~400pc to sigma-Orionis. Each observation in each filter will be done using one orbit to account for ~1600 s on target plus overheads (6.5 minutes acquisition plus dithering overheads). Indeed, the targets are visible for 52 minutes during the orbit, which are then covered by the exposure and the overheads. The exposure time estimate is based on the observations by Bally et al. (2012), which are reported by Kim et al. (2016) to be appropriate to detect proplyds. We will use short sub-exposures of length between ~400 s and then combine the various subexposures to get to the final deep image. Between exposures, we will perform a dither pattern. This will be planned with particular attention to recovering the spatial resolution, accounting for the fact that the PSF is slightly undersampled. This will also be important for the mitigation of image defects. The short exposures are needed to avoid saturation, which happens after 3600 s on our targets but could happen on shorter exposures for other stars in the field of view. In particular, the field including the massive sigma-Ori star will be observed adding two shorter exposures (30s), one at the beginning and one at the end of the 4 dithers, and positioning the massive star in the region between the two CCDs to avoid saturation. For the rest of the fields (without the massive star SOri) we choose dithering pattern parameters such that they fill the chip gap. The observations will not have to be scheduled in consecutive orbits, we will be able to combine data in the different filters also taken with time separation between them. However, consecutive observations in the three filters allow for minimizing the telescope overheads. ------------------------------------------------------------------------------------ 18093( 5) - 04-Feb-2026 21:19:58 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 W96-RJ053833 STAR, PRE-MAIN SEQUENCE RA=05H38M33.5400S, J2000 V = 16.39 -0236 STAR DEC=-02D35'56.30" Reference Frame: Other: SIMBAD Extended: NO 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) 2015.5 1.988730393638058E-5 8.55E-4 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 5 W96-4771-105 STAR, PRE-MAIN SEQUENCE RA=05H38M44.2360S, J2000 V = 14.02 1 STAR DEC=-02D40'19.79" Reference Frame: Other: SIMBAD 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) 2015.5 9.737254533676857E-5 -0.001009000038720842 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 6 HARO-5-13 STAR, PRE-MAIN SEQUENCE RA=05H38M40.2744S, J2000 V = 15.49 STAR DEC=-02D30'18.57" Reference Frame: Other: SIMBAD 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) 2015.5 5.8122214595734707E-5 -6.099999609432416E-4 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 8 -SIG-ORI STAR, PRE-MAIN SEQUENCE RA=05H38M44.7654S, J2000 V = 3.79 STAR DEC=-02D36'0.28" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. SIMBAD listed proper motion for this target. When retrieving targets with PM from SIMBAD, APT requests the coordinates be calculated with an epoch of the year 2000. Do not modify this epoch. Always review coordinates using the Target Confirmation tool, which graphically displays the PM. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 3.06982702838751E-4 -3.9999993077799445E-4 0.00304 ------------------------------------------------------------------------------------------------------------------------------------ 18093( 5) - 04-Feb-2026 21:19:58 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 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_Comments: This pattern is to be used in the field where the sigma-Ori massive star is (Left Field). We do not want to fill the chip gap. We want to position the massive star between the chip gap ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 2 Line_Spacing 0.8 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO Pattern_Comments: This pattern is to be used in the fields without the sigma-Ori massive star (Right, North, and South Fields). We do want to fill the chip gap. ------------------------------------------------------------------------------------------------------------------------------------ 18093( 5) - 04-Feb-2026 21:19:58 - [ 5] Visit: 01 (Left.Visit1) 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 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F656N FLASH=20 1 30 S (30 POS TARG -20, null S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F656N FLASH=16 1 400 S POS TARG -20, null; S ER (1600 S) PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F656N FLASH=20 1 30 S (30 POS TARG -20, null S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ -SIG-ORI 1 WFC3/UVI ACCUM UVIS-CEN F656N none none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F656N 1 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F656N 2 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F656N 3 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F656N 4 none none none 1 N/A S TER -SIG-ORI 3 WFC3/UVI ACCUM UVIS-CEN F656N none none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 6] Visit: 02 (Left.Visit1) 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 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F631N FLASH=20 1 30 S (30 POS TARG -20, null S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F631N FLASH=16 1 400 S POS TARG -20, null; S ER (1600 S) PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F631N FLASH=20 1 30 S (30 POS TARG -20, null S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ -SIG-ORI 1 WFC3/UVI ACCUM UVIS-CEN F631N none none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F631N 1 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F631N 2 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F631N 3 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F631N 4 none none none 1 N/A S TER -SIG-ORI 3 WFC3/UVI ACCUM UVIS-CEN F631N none none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 7] Visit: 03 (Left.Visit1) 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 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F658N FLASH=20 1 30 S (30 POS TARG -20, null S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F658N FLASH=16 1 400 S POS TARG -20, null; S ER (1600 S) PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 -SIG-ORI WFC3/UVI ACCUM UVIS-CENT F658N FLASH=20 1 30 S (30 POS TARG -20, null S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ -SIG-ORI 1 WFC3/UVI ACCUM UVIS-CEN F658N none none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F658N 1 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F658N 2 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F658N 3 none none none 1 N/A S TER -SIG-ORI 2 WFC3/UVI ACCUM UVIS-CEN F658N 4 none none none 1 N/A S TER -SIG-ORI 3 WFC3/UVI ACCUM UVIS-CEN F658N none none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 8] Visit: 04 (Right.Visit4) 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 W96-RJ05383 WFC3/UVI ACCUM UVIS-CENT F656N FLASH=16 1 450 S PATTERN 3 1 3-0236 S ER (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F656N 3 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F656N 4 none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 9] Visit: 05 (Right.Visit5) 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 W96-RJ05383 WFC3/UVI ACCUM UVIS-CENT F631N FLASH=16 1 450 S PATTERN 3 1 3-0236 S ER (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F631N 1 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F631N 2 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F631N 3 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F631N 4 none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 10] Visit: 06 (Right.Visit6) 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 W96-RJ05383 WFC3/UVI ACCUM UVIS-CENT F658N FLASH=16 1 450 S PATTERN 3 1 3-0236 S ER (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F658N 1 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F658N 2 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F658N 3 none none none 1 N/A S TER W96-RJ053833-0236 1 WFC3/UVI ACCUM UVIS-CEN F658N 4 none none none 1 N/A S TER 18093( 5) - 04-Feb-2026 21:19:58 - [ 11] Visit: 07 (North.Visit7) 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 HARO-5-13 WFC3/UVI ACCUM UVIS2-FIX F656N FLASH=16 1 450 S PATTERN 3 1 S (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F656N 1 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F656N 2 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F656N 3 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F656N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 12] Visit: 08 (North.Visit8) 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 HARO-5-13 WFC3/UVI ACCUM UVIS2-FIX F631N FLASH=16 1 450 S PATTERN 3 1 S (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F631N 1 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F631N 2 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F631N 3 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F631N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 13] Visit: 09 (North.Visit9) 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 HARO-5-13 WFC3/UVI ACCUM UVIS2-FIX F658N FLASH=16 1 450 S PATTERN 3 1 S (1800 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 | ------------------------------------------------------------------------------------------------------------------------------------ HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F658N 1 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F658N 2 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F658N 3 none none none 1 N/A S X HARO-5-13 1 WFC3/UVI ACCUM UVIS2-FI F658N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 14] Visit: 10 (South.Visit10) 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 W96-4771-10 WFC3/UVI ACCUM UVIS1-FIX F656N FLASH=16 1 450 S POS TARG 40, -25; 51 S (1800 S) PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F656N 1 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F656N 2 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F656N 3 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F656N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 15] Visit: 11 (South.Visit11) 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 W96-4771-10 WFC3/UVI ACCUM UVIS1-FIX F631N FLASH=16 1 450 S POS TARG 40, -25; 51 S (1800 S) PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F631N 1 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F631N 2 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F631N 3 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F631N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 16] Visit: 12 (South.Visit12) 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 W96-4771-10 WFC3/UVI ACCUM UVIS1-FIX F658N FLASH=16 1 450 S POS TARG 40, -25; 51 S (1800 S) PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F658N 1 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F658N 2 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F658N 3 none none none 1 N/A S X W96-4771-1051 1 WFC3/UVI ACCUM UVIS1-FI F658N 4 none none none 1 N/A S X 18093( 5) - 04-Feb-2026 21:19:58 - [ 17] Summary Form for Proposal 18093 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER, UVIS1-FIX, UVIS2-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=16, FLASH=20 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 2, PATTERN 3 1, POS TARG -20, null, POS TARG 40, -25 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F631N, F656N, F658N ------------------------------------------------------------------------------------------------------------------------------------ Target Names -SIG-ORI, HARO-5-13, W96-4771-1051, W96-RJ053833-0236 ------------------------------------------------------------------------------------------------------------------------------------