17807( 15) - 06-Oct-2025 19:24:06 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17807 Version: 15 Check-in Time: 06-Oct-2025 19:24:06 STScI Edit Number: 0 Title Flash Thursday: Early-time UV Spectroscopy of Type II Supernovae with HST ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Wynn Vicente Jacobson-Galan California Institute of Technology Y CoI: Mr. Kaustav Kashyap Das California Institute of Technology Y CoI: Dr. Mansi Kasliwal California Institute of Technology N CoI: Dr. Luc Dessart CNRS, Institut d'Astrophysique de Paris N CoI: Dr. Raffaella Margutti University of California - Berkeley N CoI: Prof. Ryan Chornock University of California - Berkeley N CoI: Prof. Ryan Foley University of California - Santa Cruz N CoI: Dr. Ori Dosovitz Fox Space Telescope Science Institute N CoI: Dr. Armin Rest Space Telescope Science Institute N CoI: Dr. Charles Kilpatrick Northwestern University N CoI: Dr. Matthew Ryan Siebert Space Telescope Science Institute N CoI: Kyle Davis University of California - Santa Cruz N CoI: Dr. Qinan Wang Massachusetts Institute of Technology N CoI: Dr. Adam Miller Northwestern University N CoI: Dr. Jesper Sollerman Stockholm University N CoI: Mr. Erez Arie Zimmerman Weizmann Institute of Science N CoI: Prof. Avishay Gal-Yam Weizmann Institute of Science N CoI: Dr. Andrew S. Fruchter Space Telescope Science Institute N CoI: Dr. Christoffer Fremling California Institute of Technology N ------------------------------------------------------------------------------------ Abstract Ultraviolet (UV) spectroscopy of type II supernovae (SNe II) in the first week post-explosion remains a largely uncharted observational phase space. Following red supergiant shock breakout, early-time UV emission harbors unique information on the structure and composition of the most local progenitor environment; this being detectable through narrow emission lines (aka. IIn-like or "flash features") that arise from shock ionization of local circumstellar material (CSM). Furthermore, UV spectroscopy of young core-collapse SNe encapsulates the interplay of density, ionization, and temperature within the outermost layers of SN ejecta. Here we propose UV/optical spectral observations with the HST STIS CCD through the Flex Thursday ToO program to obtain up to 7 spectra of SNe II in the first week after explosion. This program will increase the number of SNe II with early UV spectroscopy by more than a factor of 2, enabling precise constraints to be placed on the diversity of red supergiant atmospheres and SN II ejecta structure through the use of radiation hydrodynamics and nLTE radiative transfer codes (e.g., HERACLES, CMFGEN). Furthermore, this program will be essential preparation for the planned launch of the Ultraviolet Explorer (UVEX) telescope and its study of SNe II through UV spectroscopy. ------------------------------------------------------------------------------------ Observations Description ------------------------ 17807( 15) - 06-Oct-2025 19:24:06 - [ 2] ToO program through flex thursday ------------------------------------------------------------------------------------ 17807( 15) - 06-Oct-2025 19:24:06 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 9 ZTF24ABYMEET STAR, SUPERNOVA TYPE II RA=22H26M1.5800S, J2000 V = 18 DEC=+37D36'7.45" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 10 2025NGI EXT-STAR, SUPERNOVA RA=21H12M11.0000S, J2000 V = 18 DEC=-57D16'17.67" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 11 2025RYZ EXT-STAR, SUPERNOVA RA=22H08M44.8700S, J2000 V = 18 DEC=-27D51'12.97" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 12 2025WHV EXT-STAR, SUPERNOVA RA=23H20M30.5300S, J2000 V = 18 DEC=+12D14'30.23" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13 ZTF25ABVBCZT EXT-STAR, SUPERNOVA RA=03H32M7.9800S, J2000 V = 18 DEC=+41D35'45.57" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17807( 15) - 06-Oct-2025 19:24:06 - [ 4] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 1 SUPERNOVA1 EXT-STAR, SUPERNOVA TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 2 SUPERNOVA2 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 3 SUPERNOVA3 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 4 SUPERNOVA4 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 5 SUPERNOVA5 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 6 SUPERNOVA6 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 7 SUPERNOVA7 TOO V = 18 ------------------------------------------------------------------------------------------------------------------------------------ 17807( 15) - 06-Oct-2025 19:24:06 - [ 5] Visit: 01 (ToO-1) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 ZTF24ABYMEE STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ZTF24ABYMEE STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1950 S T (1950 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ZTF24ABYMEE STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ZTF24ABYMEE STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1795 S T (1795 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 ZTF24ABYMEE STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1069 S T (1069 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ZTF24ABYMEE STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1068 S T (1068 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 DEF (0 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 | ------------------------------------------------------------------------------------------------------------------------------------ ZTF24ABYMEET 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A ZTF24ABYMEET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A ZTF24ABYMEET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A ZTF24ABYMEET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A ZTF24ABYMEET 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A ZTF24ABYMEET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A ZTF24ABYMEET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A ZTF24ABYMEET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A ZTF24ABYMEET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A ZTF24ABYMEET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A ZTF24ABYMEET 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A ZTF24ABYMEET 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 6] Visit: 02 (ToO-2) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 2025NGI STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 2025NGI STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1970 S (1970 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 2025NGI STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 2025NGI STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1890 S (1890 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 2025NGI STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1080 S (1080 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 2025NGI STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1080 S (1080 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 DEF (0 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2025NGI 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 2025NGI 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A 2025NGI 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A 2025NGI 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A 2025NGI 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A 2025NGI 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A 2025NGI 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A 2025NGI 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A 2025NGI 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A 2025NGI 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A 2025NGI 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A 2025NGI 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 7] Visit: 03 (ToO-3) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 2025RYZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 2025RYZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1945 S (1945 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 2025RYZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 2025RYZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1865 S (1865 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 2025RYZ STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1080 S (1080 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 2025RYZ STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1060 S (1060 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 25 S (50 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2025RYZ 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 2025RYZ 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A 2025RYZ 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A 2025RYZ 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A 2025RYZ 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A 2025RYZ 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A 2025RYZ 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A 2025RYZ 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A 2025RYZ 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A 2025RYZ 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A 2025RYZ 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A 2025RYZ 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 8] Visit: 04 (ToO-4) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 2025WHV STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 2025WHV STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1910 S (1910 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 2025WHV STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 2025WHV STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1758 S (1758 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 2025WHV STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1050 S (1050 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 2025WHV STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1049 S (1049 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 25 S (50 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2025WHV 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 2025WHV 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A 2025WHV 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A 2025WHV 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A 2025WHV 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A 2025WHV 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A 2025WHV 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A 2025WHV 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A 2025WHV 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A 2025WHV 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A 2025WHV 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A 2025WHV 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 9] Visit: 05 (ToO-5) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 ZTF25ABVBCZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1914 S T (1914 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ZTF25ABVBCZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1760 S T (1760 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 ZTF25ABVBCZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 6 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1760 S T (1760 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 ZTF25ABVBCZ STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 T S) ------------------------------------------------------------------------------------------------------------------------------------ 8 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1760 S T (1760 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1062 S T (1062 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 ZTF25ABVBCZ STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1040 S T (1040 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 CCDFLAT STIS/CCD ACCUM 52X0.1 G750L 7751 2 25 S (50 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 | ------------------------------------------------------------------------------------------------------------------------------------ ZTF25ABVBCZT 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A ZTF25ABVBCZT 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A ZTF25ABVBCZT 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ZTF25ABVBCZT 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A ZTF25ABVBCZT 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A ZTF25ABVBCZT 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A ZTF25ABVBCZT 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A ZTF25ABVBCZT 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A ZTF25ABVBCZT 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A ZTF25ABVBCZT 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 N/A ZTF25ABVBCZT 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 N/A ZTF25ABVBCZT 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 3 N/A ZTF25ABVBCZT 7 STIS/CCD ACQ F28X50LP MIRROR none none none none 4 N/A ZTF25ABVBCZT 8 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 4 N/A ZTF25ABVBCZT 8 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 4 N/A ZTF25ABVBCZT 8 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 4 N/A ZTF25ABVBCZT 9 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 5 N/A ZTF25ABVBCZT 9 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 5 N/A ZTF25ABVBCZT 10 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 5 N/A ZTF25ABVBCZT 10 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 5 N/A CCDFLAT 11 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 1 none 5 N/A CCDFLAT 11 STIS/CCD ACCUM 52X0.1 G750L 7751 none none 2 none 5 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 11] Visit: 06 (ToO-6) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 SUPERNOVA1 STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1925 S (1925 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SUPERNOVA1 STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1865 S (1865 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1065 S (1065 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1060 S (1060 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.2 G750L 7751 2 25 S (50 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 | ------------------------------------------------------------------------------------------------------------------------------------ SUPERNOVA1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A SUPERNOVA1 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A SUPERNOVA1 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A SUPERNOVA1 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A SUPERNOVA1 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A SUPERNOVA1 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.2 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.2 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 12] Visit: 07 (ToO-7) Visit Requirements: SCHED 100%; ON HOLD ; TOO FLEX DAY On Hold Comments: Activate upon discovery of first viable target 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 SUPERNOVA1 STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1925 S (1925 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SUPERNOVA1 STIS/CCD ACQ F28X50LP MIRROR 1 2 S (2 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1865 S (1865 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G430L 4300 CR-SPLIT=2 1 1065 S (1065 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SUPERNOVA1 STIS/CCD ACCUM 52X0.2E1 G750L 7751 CR-SPLIT=2 1 1060 S (1060 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 CCDFLAT STIS/CCD ACCUM 52X0.2 G750L 7751 2 25 S (50 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 | ------------------------------------------------------------------------------------------------------------------------------------ SUPERNOVA1 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 N/A SUPERNOVA1 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 N/A SUPERNOVA1 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 N/A SUPERNOVA1 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 N/A SUPERNOVA1 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 N/A SUPERNOVA1 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 N/A SUPERNOVA1 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 1 3 N/A SUPERNOVA1 6 STIS/CCD ACCUM 52X0.2E1 G750L 7751 none none none 2 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.2 G750L 7751 none none 1 none 3 N/A CCDFLAT 7 STIS/CCD ACCUM 52X0.2 G750L 7751 none none 2 none 3 N/A 17807( 15) - 06-Oct-2025 19:24:06 - [ 13] Summary Form for Proposal 17807 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.1, 52X0.2, 52X0.2E1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2, CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ON HOLD , SCHED 100%, TOO FLEX DAY ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G230LB, G430L, G750L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2025NGI, 2025RYZ, 2025WHV, CCDFLAT, SUPERNOVA1, ZTF24ABYMEET, ZTF25ABVBCZT ------------------------------------------------------------------------------------------------------------------------------------