18049( 10) - 21-Apr-2026 19:05:09 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18049 Version: 10 Check-in Time: 21-Apr-2026 19:05:09 STScI Edit Number: 4 Title Multi-Epoch UV Spectroscopy of Young Tidal Disruption Events ------------------------------------------------------------------------------------ Type Cycle GO 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Erica Hammerstein University of California - Berkeley Y CoI: Dr. Stephen Bradley Cenko NASA Goddard Space Flight Center N CoI: Prof. Ryan Chornock University of California - Berkeley N CoI: Dr. Yuhan Yao University of California - Berkeley N CoI: Dr. Robert Stein University of Maryland N CoI: Dr. Raffaella Margutti University of California - Berkeley N CoI: Jean Somalwar University of California - Berkeley N CoI: Mr. Itai Sfaradi University of California - Berkeley N CoI: Dr. Suvi Gezari University of Maryland N CoI: Igor Andreoni University of North Carolina at Chapel N Hill ------------------------------------------------------------------------------------ Abstract When a star wanders too close to a supermassive black hole (SMBH), it can be torn apart by the tidal forces it experiences. This process can create luminous flares of radiation across the electromagnetic spectrum, and spark a multitude of phenomena such as outflows and jets. Despite predictions that these transients would be primarily X-ray ones, in recent years most tidal disruption events (TDEs) have been discovered in the optical/UV with no consensus on the origin of this emission. These large samples of TDEs can be used to probe the SMBH mass function to great distances and smaller masses, as the timing of the optical/UV light curve can be used to weigh the SMBH and probe its spin. This is only possible if we can understand the origin of the optical/UV emission. With this Cycle 33 program, we propose to observe a sample of young TDEs discovered before peak using STIS to obtain UV spectra. The UV spectra can probe the existence, evolution, and properties of outflows. By observing the evolution of outflows from pre-to-post-peak in TDEs, we can test the models for the optical/UV emission and thereby making great strides toward the goal of using TDEs as indepedent probes of SMBH properties. This goal is especially pressing in the era of upcoming, wide-field surveys and NASA missions which will discover hundreds to thousands of new TDEs. ------------------------------------------------------------------------------------ Observations Description ------------------------ This proposal consists of three disruptive STIS ToO observations 3 different infant tidal disruption events (TDEs), each followed by two additional epochs of observations spaced by ~30 days and ~90 days after the first trigger. Each trigger will be for a TDE that is spectroscopically confirmed and has a rising optical light curve. 18049( 10) - 21-Apr-2026 19:05:09 - [ 2] Each object will have the following epochs, which amount to a total of 10 orbits for each object: - first epoch: 2 orbits, the first using the STIS/NUV-MAMA using G230L; the second using the STIS/FUV-MAMA and G140L; both with the 52x0.2 aperture - second epoch (~30 days after first epoch): one visit with 2 orbits using the STIS/NUV-MAMA using G230L; another visit of 2 orbits executed within a day of the NUV visit using the STIS/FUV-MAMA and G140L; both with the 52x0.2 aperture - third epoch (~90 days after first epoch): one visit with 2 orbits using the STIS/NUV-MAMA using G230L; another visit of 2 orbits executed within a day of the NUV visit using the STIS/FUV-MAMA and G140L; both with the 52x0.2 aperture Each visit requires an ACQ in the first orbit. As these are ToO observations, we do not yet know the exact brightness of the TDE or the host. We expect that the TDE will be a UV-bright point source in the nucleus of redder galaxy. The ACQ process uses the STIS/CCD with the F28X50LP filter, but the host galaxy may dominate in the optical. I have entered placeholder parameters for a diffuse acquisition. The exposure times and checkbox size may be adjusted depending on the actual properties of the target, but we have provided ETC calculations based off a sample target. A ToO Activation on INFANT-TDE1 should activate Visit 01, Visits 04 and 05 ~30 days later, and Visits 10 and 11 ~90 days after Visit 01. A ToO Activation on INFANT-TDE2 should activate Visit 02, Visits 06 and 07 ~30 days later, and Visits 12 and 13 ~90 days after Visit 02. A ToO Activation on INFANT-TDE3 should activate Visit 03, Visits 08 and 09 ~30 days later, and Visits 14 and 15 ~90 days after Visit 03. ------------------------------------------------------------------------------------ 18049( 10) - 21-Apr-2026 19:05:09 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 4 TDE2025AARM GALAXY, ACCRETION DISK, RA=04H32M12.3900S, J2000 V = 16 +/- 1 NUCLEUS DEC=-05D22'39.59" Reference Frame: ICRS 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 TDE2026HDO GALAXY, ACCRETION DISK, RA=10H31M52.6500S, J2000 V = 19.5 +/- 0.5 NUCLEUS DEC=+73D58'5.68" Reference Frame: ICRS Comments: The source is currently on the rise, so will likely be brighter by the time of observation. 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 ------------------------------------------------------------------------------------------------------------------------------------ 18049( 10) - 21-Apr-2026 19:05:09 - [ 4] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 1 INFANT-TDE1 GALAXY, ACCRETION DISK, SPECTROSCOPICALLY CONFIRMED TDE V = 18.0 +/- 1.5 NUCLEUS, WIND WITH RISING OPTICAL LIGHT CURVE ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE2 GALAXY, ACCRETION DISK, SPECTROSCOPICALLY CONFIRMED TDE V = 18.0 +/- 1.5 NUCLEUS, WIND WITH RISING OPTICAL LIGHT CURVE ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 GALAXY, ACCRETION DISK, SPECTROSCOPICALLY CONFIRMED TDE V = 18.0 +/- 1.5 NUCLEUS, WIND WITH RISING OPTICAL LIGHT CURVE ------------------------------------------------------------------------------------------------------------------------------------ 18049( 10) - 21-Apr-2026 19:05:09 - [ 5] Visit: 01 (TDE1 Epoch 1) Visit Requirements: TOO RESPONSE TIME 7.0D 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 TDE2025AARM STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, 1 10 S (10 DIFFUSE-CENTER=FLUX-CENTROID, S) CHECKBOX=13 ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2025AARM STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (2050 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2025AARM STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2569 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2025AARM 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2025AARM 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2050.0 S -MAMA TDE2025AARM 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2569.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 6] Visit: 02 (TDE2 Epoch 1) Visit Requirements: TOO RESPONSE TIME 7.0D 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 TDE2026HDO STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID, S) CHECKBOX=13 ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2026HDO STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2026HDO STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2026HDO 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2026HDO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1892.0 S -MAMA TDE2026HDO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 7] Visit: 03 (TDE3 Epoch 1) Visit Requirements: TOO RESPONSE TIME 7.0D 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 INFANT-TDE3 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID, S) CHECKBOX=13 ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ INFANT-TDE3 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A INFANT-TDE3 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1892.0 S -MAMA INFANT-TDE3 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 8] Visit: 04 (TDE1 Epoch 2 NUV) Visit Requirements: AFTER 01 BY 270 D TO 290 D; SEQ 04, 05 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 TDE2025AARM STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2025AARM STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1890 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2025AARM STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2569 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2025AARM 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2025AARM 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1890.0 S -MAMA TDE2025AARM 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2569.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 9] Visit: 05 (TDE1 Epoch 2 FUV) Visit Requirements: AFTER 01 BY 270 D TO 290 D; SEQ 04, 05 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2025AARM STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2025AARM STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (1890 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2025AARM STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2569 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2025AARM 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2025AARM 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 1890.0 S -MAMA TDE2025AARM 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2569.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 10] Visit: 06 (TDE2 Epoch 2 NUV) Visit Requirements: BETWEEN 15-MAY-2026 AND 25-MAY-2026; SEQ 06, 07 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2026HDO STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 57 S (57 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2026HDO STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (2006 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2026HDO STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2713 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2026HDO 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2026HDO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 2006.0 S -MAMA TDE2026HDO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2713.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 11] Visit: 07 (TDE2 Epoch 2 FUV) Visit Requirements: BETWEEN 15-MAY-2026 AND 25-MAY-2026; SEQ 06, 07 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2026HDO STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 57 S (57 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2026HDO STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (2006 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2026HDO STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2713 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2026HDO 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2026HDO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 2006.0 S -MAMA TDE2026HDO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2713.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 12] Visit: 08 (TDE3 Epoch 2 NUV) Visit Requirements: AFTER 03 BY 25 D TO 35 D; SEQ 08, 09 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 INFANT-TDE3 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ INFANT-TDE3 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A INFANT-TDE3 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1892.0 S -MAMA INFANT-TDE3 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 13] Visit: 09 (TDE3 Epoch 2 FUV) Visit Requirements: AFTER 03 BY 25 D TO 35 D; SEQ 08, 09 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 INFANT-TDE3 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ INFANT-TDE3 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A INFANT-TDE3 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 1892.0 S -MAMA INFANT-TDE3 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 14] Visit: 10 (TDE1 Epoch 3 NUV) Visit Requirements: AFTER 04 BY 30 D TO 90 D; SEQ 10, 11 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 TDE2025AARM STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2025AARM STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1890 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2025AARM STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2569 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2025AARM 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2025AARM 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1890.0 S -MAMA TDE2025AARM 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2569.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 15] Visit: 11 (TDE1 Epoch 3 FUV) Visit Requirements: AFTER 05 BY 30 D TO 400 D; SEQ 10, 11 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2025AARM STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2025AARM STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (1890 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2025AARM STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2569 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2025AARM 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2025AARM 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 1890.0 S -MAMA TDE2025AARM 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2569.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 16] Visit: 12 (TDE2 Epoch 3 NUV) Visit Requirements: BETWEEN 15-AUG-2026 AND 29-AUG-2026; SEQ 12, 13 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2026HDO STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2026HDO STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2026HDO STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2026HDO 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2026HDO 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1892.0 S -MAMA TDE2026HDO 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 17] Visit: 13 (TDE2 Epoch 3 FUV) Visit Requirements: BETWEEN 15-AUG-2026 AND 29-AUG-2026; SEQ 12, 13 WITHIN 7 D; TOO RESPONSE TIME 25.0D 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 TDE2026HDO STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 TDE2026HDO STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 TDE2026HDO STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ TDE2026HDO 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A TDE2026HDO 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 1892.0 S -MAMA TDE2026HDO 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 18] Visit: 14 (TDE3 Epoch 3 NUV) Visit Requirements: AFTER 08 BY 55 D TO 65 D; SEQ 14, 15 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 INFANT-TDE3 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 STIS/NUV ACCUM 52X0.2 G230L 2376 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ INFANT-TDE3 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A INFANT-TDE3 2 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 1 1892.0 S -MAMA INFANT-TDE3 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 19] Visit: 15 (TDE3 Epoch 3 FUV) Visit Requirements: AFTER 09 BY 55 D TO 65 D; SEQ 14, 15 WITHIN 1 D; TOO RESPONSE TIME 25.0D 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 INFANT-TDE3 STIS/CCD ACQ F28X50LP MIRROR ACQTYPE=DIFFUSE, CHECKBOX=13, 1 50 S (50 DIFFUSE-CENTER=FLUX-CENTROID S) ------------------------------------------------------------------------------------------------------------------------------------ 2 INFANT-TDE3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 2160 S -MAMA see below (1892 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 INFANT-TDE3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 2640 S -MAMA see below (2571 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 | ------------------------------------------------------------------------------------------------------------------------------------ INFANT-TDE3 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A INFANT-TDE3 2 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 1892.0 S -MAMA INFANT-TDE3 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 2571.0 S -MAMA 18049( 10) - 21-Apr-2026 19:05:09 - [ 20] Summary Form for Proposal 18049 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=DIFFUSE, CHECKBOX=13, DIFFUSE-CENTER=FLUX-CENTROID ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 270 D TO 290 D, AFTER 03 BY 25 D TO 35 D, AFTER 04 BY 30 D TO 90 D, AFTER 05 BY 30 D TO 400 D, AFTER 08 BY 55 D TO 65 D, AFTER 09 BY 55 D TO 65 D, BETWEEN 15-AUG-2026 AND 29-AUG-2026, BETWEEN 15-MAY-2026 AND 25-MAY-2026, SEQ 04, 05 WITHIN 1 D, SEQ 04, 05 WITHIN 7 D, SEQ 06, 07 WITHIN 7 D, SEQ 08, 09 WITHIN 1 D, SEQ 10, 11 WITHIN 1 D, SEQ 10, 11 WITHIN 7 D, SEQ 12, 13 WITHIN 7 D, SEQ 14, 15 WITHIN 1 D, TOO RESPONSE TIME 25.0D, TOO RESPONSE TIME 7.0D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names INFANT-TDE3, TDE2025AARM, TDE2026HDO ------------------------------------------------------------------------------------------------------------------------------------