18436( 2) - 18-Aug-2026 14:43:51 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18436 Version: 2 Check-in Time: 18-Aug-2026 14:43:51 STScI Edit Number: 0 Title Imaging Six Young Planetary-Mass Companions with HST/WFC3-UVIS ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Lillian Yushu Jiang University of California - Santa Barbara Y CoI: Dr. Brendan Bowler University of California - Santa Barbara N CoI: Dr. Michael C. Liu University of Hawaii N CoI: Claire Finley University of California - Santa Barbara N ------------------------------------------------------------------------------------ Abstract Young giant planets encode their formation histories in their accretion history, but recovering accretion rates requires isolating the accretion continuum. The missing piece is UV coverage: only the UV Balmer continuum directly traces Lacc and the shock temperature structure, avoiding the order-of-magnitude uncertainty in current Halpha-based bolometric corrections. We propose consecutive-orbit HST/WFC3/UVIS imaging in F336W and F656N for six wide-orbit planetary-mass companions (3-18 MJup, q~0.005-0.08) spanning BD to K-type hosts. This program will (1) distinguish planetary-shock from magnetospheric accretion; and (2) anchor the LHalpha-Lacc relation across a broad host-mass range, providing the bolometric correction needed for current and upcoming Halpha surveys with MagAO-X, MUSE, and the ELT. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will observe six systems with WFC3/UVIS using two consecutive orbits per system. The primary goals are to measure the Balmer-continuum excess with F336W, H-alpha emission with F656N, and the companion photospheric emission with F555W together with either F775W or F850LP. The bright host stars are intentionally allowed to saturate, and repeated exposures use a three-point dither pattern. The allowed telescope orientation ranges are selected to prevent saturated-host bleeding columns from overlapping the companions while retaining broad scheduling flexibility. ROXs 12, YSES 1, and ITG 15 are observed with F336W, F656N, F555W, and F775W. Their exposure times are designed to detect the companion photosphere at signal-to-noise ratios greater than 5 in both continuum filters. Kointreau-1 and Kointreau-3 are highly extincted, so F336W and F555W are omitted. F850LP provides the photospheric anchor, and the remaining time is assigned to F656N. ROXs 42B has relatively low extinction, but an F555W detection would require too much observing time. We therefore obtain a signal-to-noise ratio greater than 5 in F775W and use the remaining time to strengthen the F336W and especially the F656N constraints. Post-flash levels are selected to produce a total background of approximately 20 electrons per pixel and reduce charge-transfer-efficiency losses. ------------------------------------------------------------------------------------ 18436( 2) - 18-Aug-2026 14:43:51 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 KOINTREAU-1 STAR, EXTRA-SOLAR RA=04H33M26.2192S, J2000 G = 16.52 mag PLANETARY SYSTEM, LOW DEC=+22D45'29.26" MASS COMPANION, PRE-MAIN SEQUENCE STAR, YSO 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 6.434266003599132E-4 -0.016525999922123447 0.0062913 ------------------------------------------------------------------------------------------------------------------------------------ 2 KOINTREAU-3 STAR, EXTRA-SOLAR RA=16H27M4.5157S, J2000 R=16.69 mag PLANETARY SYSTEM, LOW DEC=-24D42'59.67" MASS COMPANION, PRE-MAIN SEQUENCE STAR, YSO 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 -4.7542131847042507E-4 -0.02496700001302088 0.0072555 ------------------------------------------------------------------------------------------------------------------------------------ 18436( 2) - 18-Aug-2026 14:43:51 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 3 ITG-15 STAR, EXTRA-SOLAR RA=04H39M44.8814S, J2000 G = 14.98mag PLANETARY SYSTEM, LOW DEC=+26D01'52.71" MASS COMPANION 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 4.961302444978328E-4 -0.021949000006316055 0.0071594 ------------------------------------------------------------------------------------------------------------------------------------ 4 YSES-1 STAR, EXTRA-SOLAR RA=13H25M12.1263S, J2000 V = 11.12 PLANETARY SYSTEM, LOW DEC=-64D56'20.69" MASS COMPANION, PRE-MAIN SEQUENCE STAR, YSO 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 -0.006452278251415972 -0.017733999970914738 0.0106124 ------------------------------------------------------------------------------------------------------------------------------------ 18436( 2) - 18-Aug-2026 14:43:51 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 5 ROXS-12 STAR, EXTRA-SOLAR RA=16H26M28.0397S, J2000 V = 14.29 PLANETARY SYSTEM, LOW DEC=-25D26'47.72" MASS COMPANION, PRE-MAIN SEQUENCE STAR 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 -5.06320022034709E-4 -0.02481500005160342 0.0072169999999999995 ------------------------------------------------------------------------------------------------------------------------------------ 6 ROXS-42B STAR, EXTRA-SOLAR RA=16H31M15.0183S, J2000 V = 14.27 PLANETARY SYSTEM, LOW DEC=-24D32'43.72" MASS COMPANION, PRE-MAIN SEQUENCE STAR 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 -4.2009670509298255E-4 -0.02336600002763589 0.0068284 ------------------------------------------------------------------------------------------------------------------------------------ 18436( 2) - 18-Aug-2026 14:43:51 - [ 5] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 18436( 2) - 18-Aug-2026 14:43:51 - [ 6] Visit: 01 Visit Requirements: ORIENT 97D TO 257 D; ORIENT 277D TO 77 D On Hold Comments: Additional Comments: KOINTREAU-1 b: two consecutive orbits. Orbit 1 F850LP+F656N; Orbit 2 F656N. F336W and F555W omitted because of high extinction. Saturated primary is intentional. ORIENT ranges for saturated-primary bleed avoidance: 97-257 deg and 277-77 deg. 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 KOINTREAU-1 WFC3/UVI ACCUM UVIS2-C51 F850LP FLASH=20 1 50 S (150 PATTERN 1 1 S 2C-SUB S) Comments: snr ~ 6.9 ------------------------------------------------------------------------------------------------------------------------------------ 2 KOINTREAU-1 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 729 S PATTERN 1 2 S 2C-SUB (2187 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 KOINTREAU-1 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 843 S PATTERN 1 3 S 2C-SUB (2529 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOINTREAU-1 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 1 none none none 1 N/A S 12C-SUB KOINTREAU-1 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 2 none none none 1 N/A S 12C-SUB KOINTREAU-1 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 3 none none none 1 N/A S 12C-SUB KOINTREAU-1 2 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 1 N/A S 12C-SUB KOINTREAU-1 2 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 1 N/A S 12C-SUB KOINTREAU-1 2 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 1 N/A S 12C-SUB KOINTREAU-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB KOINTREAU-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB KOINTREAU-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 7] Visit: 02 Visit Requirements: ORIENT 55D TO 215 D; ORIENT 235D TO 35 D On Hold Comments: Additional Comments: KOINTREAU-3 b: two consecutive orbits. Orbit 1 has the three-point F850LP anchor followed by one unpatterned F656N exposure that uses the remaining visibility; Orbit 2 has the three-point F656N sequence. F336W and F555W are omitted because of high extinction. Saturated primary is intentional. ORIENT ranges for saturated-primary bleed avoidance (pending PC approval): 55-215 deg and 235-35 deg 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 KOINTREAU-3 WFC3/UVI ACCUM UVIS2-C51 F850LP FLASH=12 1 600 S PATTERN 1 1 S 2C-SUB (1800 S) Comments: predicted companion S/N ~ 5.1 ------------------------------------------------------------------------------------------------------------------------------------ 2 KOINTREAU-3 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 679 S (679 SEQ 2 NON-INT S 2C-SUB S) Comments: Additional single F656N exposure using the remaining Orbit 1 visibility ------------------------------------------------------------------------------------------------------------------------------------ 3 KOINTREAU-3 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 850 S PATTERN 1 3 S 2C-SUB (2550 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 | ------------------------------------------------------------------------------------------------------------------------------------ KOINTREAU-3 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 1 none none none 1 N/A S 12C-SUB KOINTREAU-3 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 2 none none none 1 N/A S 12C-SUB KOINTREAU-3 1 WFC3/UVI ACCUM UVIS2-C5 F850LP 3 none none none 1 N/A S 12C-SUB KOINTREAU-3 2 WFC3/UVI ACCUM UVIS2-C5 F656N none none none none 1 N/A S 12C-SUB KOINTREAU-3 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB KOINTREAU-3 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB KOINTREAU-3 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 8] Visit: 03 Visit Requirements: ORIENT 115D TO 275 D; ORIENT 295D TO 95 D On Hold Comments: Additional Comments: ITG 15B: two consecutive orbits. Orbit 1 F336W+F555W; Orbit 2 F656N+F775W. The J-normalized atmosphere predicts F555W S/N about 7.2. Saturated primary is intentional. ETC v34.2 average-background FLASH checks: F336W 560 s FLASH=18 (WFC3UVIS.im.2366577), F555W 225 s FLASH=12 (WFC3UVIS.im.2366568), F656N 746 s FLASH=18 (WFC3UVIS.im.2366578), F775W 25 s FLASH=20 (WFC3UVIS.im.2366570). ORIENT ranges for saturated-primary bleed avoidance: 115-275 deg and 295-95 deg. 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 ITG-15 WFC3/UVI ACCUM UVIS2-C51 F336W FLASH=18 1 560 S PATTERN 1 1 S 2C-SUB (1680 S) Comments: Accretion-continuum exposure; zero-flash background 2.9 e-/pixel. FLASH=18 verified without a CTE warning in WFC3UVIS.im.2366577. Primary saturation allowed. ------------------------------------------------------------------------------------------------------------------------------------ 2 ITG-15 WFC3/UVI ACCUM UVIS2-C51 F555W FLASH=12 1 225 S (675 PATTERN 1 2 S 2C-SUB S) Comments: Photospheric anchor; zero-flash background 8.8 e-/pixel. FLASH=12 verified without a CTE warning in WFC3UVIS.im.2366568. J-normalized atmosphere predicts companion S/N about 7.2. ------------------------------------------------------------------------------------------------------------------------------------ 3 ITG-15 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 746 S PATTERN 1 3 S 2C-SUB (2238 S) Comments: H-alpha line exposure; zero-flash background 2.5 e-/pixel. FLASH=18 verified without a CTE warning in WFC3UVIS.im.2366578. Primary saturation allowed. ------------------------------------------------------------------------------------------------------------------------------------ 4 ITG-15 WFC3/UVI ACCUM UVIS2-C51 F775W FLASH=20 1 25 S (75 PATTERN 1 4 S 2C-SUB S) Comments: Red photospheric anchor; zero-flash background 0.66 e-/pixel. FLASH=20 verified without a CTE warning in WFC3UVIS.im.2366570. Nominal companion S/N about 24. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ ITG-15 1 WFC3/UVI ACCUM UVIS2-C5 F336W 1 none none none 1 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ITG-15 1 WFC3/UVI ACCUM UVIS2-C5 F336W 2 none none none 1 N/A S 12C-SUB ITG-15 1 WFC3/UVI ACCUM UVIS2-C5 F336W 3 none none none 1 N/A S 12C-SUB ITG-15 2 WFC3/UVI ACCUM UVIS2-C5 F555W 1 none none none 1 N/A S 12C-SUB ITG-15 2 WFC3/UVI ACCUM UVIS2-C5 F555W 2 none none none 1 N/A S 12C-SUB ITG-15 2 WFC3/UVI ACCUM UVIS2-C5 F555W 3 none none none 1 N/A S 12C-SUB ITG-15 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB ITG-15 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB ITG-15 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB ITG-15 4 WFC3/UVI ACCUM UVIS2-C5 F775W 1 none none none 2 N/A S 12C-SUB ITG-15 4 WFC3/UVI ACCUM UVIS2-C5 F775W 2 none none none 2 N/A S 12C-SUB ITG-15 4 WFC3/UVI ACCUM UVIS2-C5 F775W 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 10] Visit: 04 Visit Requirements: ORIENT 359D TO 104 D; ORIENT 124D TO 159 D; ORIENT 179D TO 284 D; ORIENT 304D TO 339 D On Hold Comments: Additional Comments: YSES 1 system: two consecutive orbits; both b and c remain in the subarray. Orbit 1 F336W+F775W; Orbit 2 F656N+F555W. Saturated primary is intentional. ORIENT ranges for saturated-primary bleed avoidance: 359-104 deg, 124-159 deg, 179-284 deg, and 304-339 deg. For companion PAs 214 deg (b) and 159 deg (c), exclude +/-10 deg around ORIENT=169/349 deg and 114/294 deg, respectively; calculation uses the WFC3/UVIS detector-column offset ORIENT=PA+135 deg. 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 YSES-1 WFC3/UVI ACCUM UVIS2-C51 F336W FLASH=16 1 784 S PATTERN 1 1 S 2C-SUB (2352 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 YSES-1 WFC3/UVI ACCUM UVIS2-C51 F775W FLASH=19 1 25 S (75 PATTERN 1 2 S 2C-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 3 YSES-1 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 698 S PATTERN 1 3 S 2C-SUB (2094 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 YSES-1 WFC3/UVI ACCUM UVIS2-C51 F555W FLASH=16 1 100 S (300 PATTERN 1 4 S 2C-SUB 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 | ------------------------------------------------------------------------------------------------------------------------------------ YSES-1 1 WFC3/UVI ACCUM UVIS2-C5 F336W 1 none none none 1 N/A S 12C-SUB YSES-1 1 WFC3/UVI ACCUM UVIS2-C5 F336W 2 none none none 1 N/A S 12C-SUB YSES-1 1 WFC3/UVI ACCUM UVIS2-C5 F336W 3 none none none 1 N/A S 12C-SUB YSES-1 2 WFC3/UVI ACCUM UVIS2-C5 F775W 1 none none none 1 N/A S 12C-SUB YSES-1 2 WFC3/UVI ACCUM UVIS2-C5 F775W 2 none none none 1 N/A S 12C-SUB YSES-1 2 WFC3/UVI ACCUM UVIS2-C5 F775W 3 none none none 1 N/A S 12C-SUB YSES-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB YSES-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB YSES-1 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 11] 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 | ------------------------------------------------------------------------------------------------------------------------------------ YSES-1 4 WFC3/UVI ACCUM UVIS2-C5 F555W 1 none none none 2 N/A S 12C-SUB YSES-1 4 WFC3/UVI ACCUM UVIS2-C5 F555W 2 none none none 2 N/A S 12C-SUB YSES-1 4 WFC3/UVI ACCUM UVIS2-C5 F555W 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 12] Visit: 05 Visit Requirements: ORIENT 17D TO 177 D; ORIENT 197D TO 357 D On Hold Comments: Additional Comments: ROXs 12 B: two consecutive orbits. Orbit 1 F336W+F555W; Orbit 2 F656N+F775W. Saturated primary is intentional. ORIENT ranges for saturated-primary bleed avoidance: 17-177 deg and 197-357 deg. 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 ROXS-12 WFC3/UVI ACCUM UVIS2-C51 F336W FLASH=18 1 525 S PATTERN 1 1 S 2C-SUB (1575 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ROXS-12 WFC3/UVI ACCUM UVIS2-C51 F555W FLASH=10 1 260 S (780 PATTERN 1 2 S 2C-SUB S) Comments: predicted companion S/N ~ 5.2. ------------------------------------------------------------------------------------------------------------------------------------ 3 ROXS-12 WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 746 S PATTERN 1 3 S 2C-SUB (2238 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ROXS-12 WFC3/UVI ACCUM UVIS2-C51 F775W FLASH=20 1 25 S (75 PATTERN 1 4 S 2C-SUB S) Comments: predicted companion S/N about 24. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ ROXS-12 1 WFC3/UVI ACCUM UVIS2-C5 F336W 1 none none none 1 N/A S 12C-SUB ROXS-12 1 WFC3/UVI ACCUM UVIS2-C5 F336W 2 none none none 1 N/A S 12C-SUB ROXS-12 1 WFC3/UVI ACCUM UVIS2-C5 F336W 3 none none none 1 N/A S 12C-SUB ROXS-12 2 WFC3/UVI ACCUM UVIS2-C5 F555W 1 none none none 1 N/A S 12C-SUB ROXS-12 2 WFC3/UVI ACCUM UVIS2-C5 F555W 2 none none none 1 N/A S 12C-SUB ROXS-12 2 WFC3/UVI ACCUM UVIS2-C5 F555W 3 none none none 1 N/A S 12C-SUB ROXS-12 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB ROXS-12 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB ROXS-12 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB ROXS-12 4 WFC3/UVI ACCUM UVIS2-C5 F775W 1 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 13] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ROXS-12 4 WFC3/UVI ACCUM UVIS2-C5 F775W 2 none none none 2 N/A S 12C-SUB ROXS-12 4 WFC3/UVI ACCUM UVIS2-C5 F775W 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 14] Visit: 06 Visit Requirements: ORIENT 53D TO 213 D; ORIENT 233D TO 33 D On Hold Comments: Additional Comments: ROXs 42B b: two consecutive orbits. Orbit 1 F336W+F775W; Orbit 2 is dedicated to F656N. F555W is omitted because a meaningful photospheric detection is too expensive. Saturated primary is intentional. ETC v34.2 average-background FLASH checks: F336W 725 s FLASH=17 (WFC3UVIS.im.2366571), F775W 55 s FLASH=19 (WFC3UVIS.im.2366579), F656N 843 s FLASH=18 (WFC3UVIS.im.2366580). ORIENT ranges for saturated-primary bleed avoidance: 53-213 deg and 233-33 deg. 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 ROXS-42B WFC3/UVI ACCUM UVIS2-C51 F336W FLASH=17 1 725 S PATTERN 1 1 S 2C-SUB (2175 S) Comments: Accretion-continuum exposure; zero-flash background 3.8 e-/pixel. FLASH=17 verified without a CTE warning in WFC3UVIS.im.2366571. ------------------------------------------------------------------------------------------------------------------------------------ 2 ROXS-42B WFC3/UVI ACCUM UVIS2-C51 F775W FLASH=19 1 55 S (165 PATTERN 1 2 S 2C-SUB S) Comments: Red photospheric anchor; zero-flash background 1.5 e-/pixel. FLASH=19 verified without a CTE warning in WFC3UVIS.im.2366579. ------------------------------------------------------------------------------------------------------------------------------------ 3 ROXS-42B WFC3/UVI ACCUM UVIS2-C51 F656N FLASH=18 1 843 S PATTERN 1 3 S 2C-SUB (2529 S) Comments: H-alpha line exposure; zero-flash background 2.8 e-/pixel. FLASH=18 verified without a CTE warning in WFC3UVIS.im.2366580. ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ ROXS-42B 1 WFC3/UVI ACCUM UVIS2-C5 F336W 1 none none none 1 N/A S 12C-SUB ROXS-42B 1 WFC3/UVI ACCUM UVIS2-C5 F336W 2 none none none 1 N/A S 12C-SUB ROXS-42B 1 WFC3/UVI ACCUM UVIS2-C5 F336W 3 none none none 1 N/A S 12C-SUB ROXS-42B 2 WFC3/UVI ACCUM UVIS2-C5 F775W 1 none none none 1 N/A S 12C-SUB ROXS-42B 2 WFC3/UVI ACCUM UVIS2-C5 F775W 2 none none none 1 N/A S 12C-SUB ROXS-42B 2 WFC3/UVI ACCUM UVIS2-C5 F775W 3 none none none 1 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 15] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ROXS-42B 3 WFC3/UVI ACCUM UVIS2-C5 F656N 1 none none none 2 N/A S 12C-SUB ROXS-42B 3 WFC3/UVI ACCUM UVIS2-C5 F656N 2 none none none 2 N/A S 12C-SUB ROXS-42B 3 WFC3/UVI ACCUM UVIS2-C5 F656N 3 none none none 2 N/A S 12C-SUB 18436( 2) - 18-Aug-2026 14:43:51 - [ 16] Summary Form for Proposal 18436 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C512C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, FLASH=12, FLASH=16, FLASH=17, FLASH=18, FLASH=19, FLASH=20 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 115D TO 275 D, ORIENT 124D TO 159 D, ORIENT 179D TO 284 D, ORIENT 17D TO 177 D, ORIENT 197D TO 357 D, ORIENT 233D TO 33 D, ORIENT 235D TO 35 D, ORIENT 277D TO 77 D, ORIENT 295D TO 95 D, ORIENT 304D TO 339 D, ORIENT 359D TO 104 D, ORIENT 53D TO 213 D, ORIENT 55D TO 215 D, ORIENT 97D TO 257 D, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, PATTERN 1 4, SEQ 2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W, F555W, F656N, F775W, F850LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names ITG-15, KOINTREAU-1, KOINTREAU-3, ROXS-12, ROXS-42B, YSES-1 ------------------------------------------------------------------------------------------------------------------------------------