18368( 3) - 25-Aug-2026 11:57:33 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18368 Version: 3 Check-in Time: 25-Aug-2026 11:57:33 STScI Edit Number: 1 Title Unprecedented Early UV Spectroscopy of a Nearby Supernova ------------------------------------------------------------------------------------ Type Cycle GO 34 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Nicolas Eduardo Meza Retamal University of California - Davis Y CoI: Dr. Aravind Pazhayath Ravi University of California - Davis N CoI: Ms. Darshana Mehta University of California - Davis N CoI: Emily Hoang University of California - Davis N CoI: Dr. Bhagya Subrayan University of Arizona N CoI: Dr. Kyra Azalee Bostroem California Institute of Technology N CoI: Dr. Conor Ransome University of Arizona N CoI: Jeniveve Pearson University of Arizona N CoI: Dr. Manisha Shrestha Monash University N CoI: Brian Hsu University of Arizona N CoI: Prof. Stefano Valenti University of California - Davis N CoI: Prof. David J. Sand University of Arizona N CoI: Dr. Andy Howell Las Cumbres Observatory Global Telescope N Network CoI: Dr. Peter J. Brown Texas A & M University N CoI: Dr. Jennifer Andrews NOIRLab - Gemini North (HI) N CoI: Prof. Griffin Hosseinzadeh University of California - San Diego N CoI: Dr. Michael Jon Lundquist California Association for Research in N Astronomy (CARA) ------------------------------------------------------------------------------------ Abstract We propose an ultra-disruptive target of opportunity (ToO) ultraviolet spectroscopic sequence of one nearby SN discovered within ~24 hours of explosion. We will fully complement these observations with a rapid response, high cadence early light curve, along with a optical+near-infrared (NIR) ground-based follow-up campaign. Our observations will provide an unprecedented view of the shock-breakout of SN explosions and the SN interaction, with either a stellar companion or circumstellar medium (CSM), and it will give key insights on the last phases of stellar evolution. At early times, our view of the SN is still incomplete, as our optical observations cover less than ~1% of the total emission. Only UV spectroscopy will allow us to put firm constraints on the physical conditions of the explosion and properties of the progenitor, like metallicity. For core-collapse SNe, the early temperature evolution can constrain the progenitor outer density profile. The UV light, or the SN ejecta, can ionize the CSM and can constrain the progenitor wind speed and CSM extent tracing back its mass-loss history. For type Ia SNe, recent very early light curve excesses point to interaction with a companion star, CSM interaction or an unusual nickel distribution, but models cannot reproduce UV light curves. Only spectroscopy will reveal the progenitors of these essential cosmological tools. Very early UV spectroscopy of a nearby SN is a completely unique observation that only HST can provide, and the SN community may not have this opportunity again for the foreseeable future. ------------------------------------------------------------------------------------ 18368( 3) - 25-Aug-2026 11:57:33 - [ 2] Observations Description ------------------------ Our primary science goal is to trace the very early spectral evolution tied to shock breakout, and CSM or companion star interaction in one very nearby supernova. These signatures disappear on 3 day timescales, aside from special cases (such as type IIn SNe), where they may persist. To do this, we need a UV spectrum as soon as possible after explosion. We also request two additional epochs of UV spectroscopy in quick succession, spaced one day apart after the initial observation and 2 other observations 7 days and 14 days after the first HST observation. Briefly, as soon as we have identified a potential SN candidate for HST we will begin communicating with our STScI Program Coordinator regarding a potential trigger and scheduling constraints. At that time we will provide coordinates and magnitude estimate. While the STScl Program coordinator will check the scheduling constraints to figured out when it will be possible to Trigger our program, we will aquire additional data to confirm that the target satisfies our triggering constraints (additional data with SWIFT, spectroscopic confirmation). This process may take up to 6-12 hours. Once we have fulfilled all of our trigger criteria described above, we will submit the APT Phase II and remain in contact with STScI throughout the process thereafter. The first epoch (with STIS/CCD) should be executed as soon as possible, with the subsequent two epochs spaced 1 day apart. Two final epochs spaced +7 and +14 days after the initial epochs ensure that we will have a full UV spectroscopic sequence. We will use STIS/CCD for all of our UV+optical (1600-5700 A) spectroscopy: time constrain (if possible) orientation constrain (if possible) 1 STIS/CCD G230LB (2.5 orbits)/G430L (0.5 orbit) 52x0.2 arcsec slit 24-36 hours from APT submission 3 orbits 2 STIS/CCD G230LB (2.5 orbits)/G430L (0.5 orbit) 52x0.2 arcsec slit +1 day from observation 1 3 orbits same as visit 1 3 STIS/CCD G230LB (2.5 orbits)/G430L (0.5 orbit) 52x0.2 arcsec slit +1 day from observation 2 3 orbits same as visit 1 4 STIS/CCD G230LB (1.5 orbits)/G430L (0.5 orbit) 52x0.2 arcsec slit +7 days from observation 3 2 orbits same as visit 1 5 STIS/CCD G230LB (1.5 orbits)/G430L (0.5 orbit) 52x0.2 arcsec slit +7 days from observation 4 2 orbits same as visit 1 NOTE THAT WE SUBMITTED 3 SET OF VISITS: 1-5 to be used in case of a faint target 6-10 to be used in case of a bright target 11-15 to be used in case of a faint target with an offset from a reference star ------------------------------------------------------------------------------------ 18368( 3) - 25-Aug-2026 11:57:33 - [ 3] TARGET LIST Generic Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Selection Criteria | Flux data No | Name | Description | | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2026XXXX EXT-STAR, SUPERNOVA YOUNG SN UV BRIGHT V = 19 ------------------------------------------------------------------------------------------------------------------------------------ 2 REFERENCE-ST STAR, UNDESIGNATED SELECTED AFTER SUITABLE SUPERNOVA V = 0 +/- 0 AR DISCOVERED Comments: Bright star to use for acquisition and offset to the supernova target ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX-O EXT-STAR, SUPERNOVA YOUNG SN UV BRIGHT WITH OFFSET V = 19 FFSET ------------------------------------------------------------------------------------------------------------------------------------ 18368( 3) - 25-Aug-2026 11:57:33 - [ 4] Visit: 01 Visit Requirements: ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 1. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 1 in the case of a FAINT target 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 662.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 6] Visit: 02 Visit Requirements: AFTER 01 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated at the same time as visit 1 NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 2 in the case of a FAINT target we would like if possible same orientation as visit 1 We would like if possible 24 hours after visit 1 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 662.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 7] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 662.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 8] Visit: 03 Visit Requirements: AFTER 02 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated at the same time as visit 1 NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 3 in the case of a FAINT target we would like if possible same orientation as visit 1 We would like if possible 48 hours after visit 2 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 662.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 662.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 10] Visit: 04 Visit Requirements: AFTER 03 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated at the same time as visit 1. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 4 in the case of a FAINT target we would like if possible same orientation as visit 1 We would like if possible 7 days after visit 3 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1986 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (774 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (816 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 662.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 662.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 387.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 387.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 408.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 408.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 11] Visit: 05 Visit Requirements: SCHED 100%; AFTER 04 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated at the same time as visit 1. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 5 in the case of a FAINT target we would like if possible same orientation as visit 1 We would like if possible 7 days after visit 4 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1884 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (718 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (760 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 628.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 628.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 628.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 359.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 359.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 380.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 12] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 380.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 13] Visit: 06 Visit Requirements: ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 06. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 1 in the case of a BRIGHT target 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (2052 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 684.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 14] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 15] Visit: 07 Visit Requirements: AFTER 06 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 06. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 2 in the case of a BRIGHT target we would like if possible same orientation than visit 6 We would like if possible 24 hours after visit 6 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (2052 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 684.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 16] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 684.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 17] Visit: 08 Visit Requirements: AFTER 07 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 06. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 3 in the case of a BRIGHT target we would like if possible same orientation than visit 6 We would like if possible 48 hours after visit 7 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (2052 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (1842 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (770 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (822 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 684.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 18] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 684.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 614.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 614.0 S SN2026XXXX 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 385.0 S SN2026XXXX 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 385.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 411.0 S SN2026XXXX 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 411.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 19] Visit: 09 Visit Requirements: AFTER 08 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 06. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 4 in the case of a BRIGHT target we would like if possible same orientation than visit 6 We would like if possible 7 days after visit 8 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (2052 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (796 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (796 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 684.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 398.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 398.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 398.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 398.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 20] Visit: 10 Visit Requirements: AFTER 09 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 06. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 5 in the case of a BRIGHT target we would like if possible same orientation than visit 6 We would like if possible 7 days after visit 9 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 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S see below (2052 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2026XXXX STIS/CCD ACQ F28X50LP MIRROR 1 17 S (17 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S see below (796 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S see below (796 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 684.0 S SN2026XXXX 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 684.0 S SN2026XXXX 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 398.0 S SN2026XXXX 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 398.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 398.0 S SN2026XXXX 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 398.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 21] Visit: 11 Visit Requirements: ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 11. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 1 in the case of a FAINT target with offset 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 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (2061 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (1944 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S OFFSET see below (820 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S OFFSET see below (872 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 | ------------------------------------------------------------------------------------------------------------------------------------ REFERENCE-STAR 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 687.0 S REFERENCE-STAR 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 648.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 648.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 22] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 648.0 S REFERENCE-STAR 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 410.0 S SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 410.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 436.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 436.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 23] Visit: 12 Visit Requirements: AFTER 11 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 11. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 2 in the case of a FAINT target with offset we would like if possible same orientation than visit 11 We would like if possible 24 hours after visit 11 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 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (2061 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (1944 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S OFFSET see below (820 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S OFFSET see below (872 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 | ------------------------------------------------------------------------------------------------------------------------------------ REFERENCE-STAR 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 687.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 687.0 S REFERENCE-STAR 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 648.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 648.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 648.0 S REFERENCE-STAR 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 410.0 S SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 410.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 436.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 436.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 25] Visit: 13 Visit Requirements: AFTER 12 BY 1 D TO 2 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 11. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 3 in the case of a FAINT target with offset we would like if possible same orientation than visit 11 We would like if possible 48 hours after visit 11 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 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (2061 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (1944 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S OFFSET see below (820 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S OFFSET see below (872 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 | ------------------------------------------------------------------------------------------------------------------------------------ REFERENCE-STAR 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 687.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 26] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 687.0 S REFERENCE-STAR 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 648.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 648.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 2 648.0 S REFERENCE-STAR 5 STIS/CCD ACQ F28X50LP MIRROR none none none none 3 N/A SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 3 410.0 S SN2026XXXX-OFFSET 6 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 3 410.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 3 436.0 S SN2026XXXX-OFFSET 7 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 3 436.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 27] Visit: 14 Visit Requirements: AFTER 13 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 11. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 4 in the case of a FAINT target with offset we would like if possible same orientation than visit 11 We would like if possible 7 days after visit 13 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 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (2061 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S OFFSET see below (846 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S OFFSET see below (846 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 | ------------------------------------------------------------------------------------------------------------------------------------ REFERENCE-STAR 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 687.0 S REFERENCE-STAR 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 423.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 423.0 S SN2026XXXX-OFFSET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 423.0 S SN2026XXXX-OFFSET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 423.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 28] Visit: 15 Visit Requirements: AFTER 14 BY 6 D TO 10 D; ON HOLD ; TOO MIN RESPONSE TIME 1.0D; TOO MAX RESPONSE TIME 2.0D On Hold Comments: Waiting for a suitable supernova to explode. This visit will be activated with Visit 11. NOTE : The minimum response time has been set to 24hrs due to the APT constrain. However, please note that due to the nature of the program we require a maximum response time of ~24hrs. Additional Comments: this is visit 5 in the case of a FAINT target with offset we would like if possible same orientation than visit 11 We would like if possible 7 days after visit 14 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 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 CR-SPLIT=3 1 1800 S OFFSET see below (2061 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 REFERENCE-S STIS/CCD ACQ F28X50LP MIRROR 1 .5 S (0.5 TAR S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G230LB 2375 1 800 S OFFSET see below (846 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2026XXXX- STIS/CCD ACCUM 52X0.2E1 G430L 4300 1 800 S OFFSET see below (846 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 | ------------------------------------------------------------------------------------------------------------------------------------ REFERENCE-STAR 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 1 687.0 S SN2026XXXX-OFFSET 2 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 3 1 687.0 S REFERENCE-STAR 3 STIS/CCD ACQ F28X50LP MIRROR none none none none 2 N/A SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 1 2 423.0 S SN2026XXXX-OFFSET 4 STIS/CCD ACCUM 52X0.2E1 G230LB 2375 none none none 2 2 423.0 S SN2026XXXX-OFFSET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 1 2 423.0 S SN2026XXXX-OFFSET 5 STIS/CCD ACCUM 52X0.2E1 G430L 4300 none none none 2 2 423.0 S 18368( 3) - 25-Aug-2026 11:57:33 - [ 29] Summary Form for Proposal 18368 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2E1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 1 D TO 2 D, AFTER 02 BY 1 D TO 2 D, AFTER 03 BY 6 D TO 10 D, AFTER 04 BY 6 D TO 10 D, AFTER 06 BY 1 D TO 2 D, AFTER 07 BY 1 D TO 2 D, AFTER 08 BY 6 D TO 10 D, AFTER 09 BY 6 D TO 10 D, AFTER 11 BY 1 D TO 2 D, AFTER 12 BY 1 D TO 2 D, AFTER 13 BY 6 D TO 10 D, AFTER 14 BY 6 D TO 10 D, ON HOLD , SCHED 100%, TOO MAX RESPONSE TIME 2.0D, TOO MIN RESPONSE TIME 1.0D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G230LB, G430L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names REFERENCE-STAR, SN2026XXXX, SN2026XXXX-OFFSET ------------------------------------------------------------------------------------------------------------------------------------