We realised that we had not correctly filled in the joint request time on the front page of the APT, although this is justified in the text. I apologise this submission is late. The only change is to add the 2 nights NOIRLab and 6.8 hours JWST requested in the text to the front page of teh APT. I Hope this is OK. 534031237 Assigned ID: 4694 ----- Attempting Submission 1 (Wed May 24 21:56:51 GMT 2023) ----- HST Phase I Proposal 4694 successfully submitted. Receipt: # 4694-1 ----- Attempting Submission 2 (Thu May 25 06:56:23 GMT 2023) ----- ORBITAL VISIBILITY OVERRUN ORBITAL VISIBILITY OVERRUN ORBITAL VISIBILITY OVERRUN Dear Bill, Please find attached the updated submission with a new visit G3 for observations of GRB 230818A in F606W. Thanks, Andrew -1618994375 ----- Attempting Submission 1 (Thu Sep 14 09:26:00 GMT 2023) ----- ----- Attempting Submission 2 (Mon Nov 27 15:28:31 GMT 2023) ----- ----- Attempting Submission 3 (Wed Dec 13 12:53:02 GMT 2023) ----- ----- Attempting Submission 4 (Wed Apr 17 15:50:14 GMT 2024) ----- ----- Attempting Submission 5 (Mon Aug 12 08:20:13 GMT 2024) ----- ----- Attempting Submission 6 (Fri Apr 25 08:15:07 GMT 2025) ----- ----- Attempting Submission 7 (Mon May 05 12:51:08 GMT 2025) ----- ----- Attempting Submission 8 (Tue Sep 16 15:15:17 GMT 2025) ----- ----- Attempting Submission 9 (Fri Feb 06 15:47:49 GMT 2026) ----- These errors refer to visits that have already executed or are not for consideration. Only G3 is relevant now. Gamma-ray burst supernovae across cosmic time Long-duration gamma-ray bursts (GRBs) are the most luminous stellar explosions in nature and are associated with the collapse of massive stars. GRBs are bright enough to see at great distances, with a median redshift of z>2 and some GRBs seen out to z>8, perhaps even z>9. Therefore, they pinpoint the locations of supernovae at distances where we have never directly observed them. Here we propose to measure the evolution of three GRB supernovae at 1.5 < z < 3 for the first time. These observations give us the ability to test if supernovae (in particular GRB-SNe) change with redshift. Differences in metallicity and stellar winds are quite likely to alter the evolution of massive stars with redshift. This is especially true if rare pathways only accessible at low metallicities, such as chemically homogeneous evolution, begin to dominate the lives of GRB progenitors. Since supernovae are a vital feedback mechanism to the interstellar and intergalactic medium via elements ejection and winds, a change in the properties of supernovae could have significant implications not only for the progenitors of GRBs but also for galaxy evolution more generally. Our photometric observations will determine the peak magnitude and decay, while a single JWST spectrum at peak will measure composition and velocities. This will provide a measurement of radioactive nickel production and luminosity. From this, we can begin to ascertain how the properties of GRB progenitors, and by extension massive stars, vary over cosmic time. Our aim is to study the evolution of GRB supernovae at 1.5 < z < 3.0 via 5 epochs of HST imaging (4 during the SN phase and one late time template). At each epoch we will obtain an optical (rest-frame UV) observation to track the afterglow and an IR (rest-frame optical) filter to track the supernova. We have set three possible set-ups depending on the redshfit of the supernova and the available ground based data (F606W/F125W, F606W/F140W and F606W/F160W) and we will use different IR filters depending on the redshift in order to track the supernova at similar rest-frame wavelengths. At each epochs we will use 1 orbit visits in each filter with a 4-point dither. The visit should be sceduled within +/- 2 days of each other. At later epochs we will switch to 2 orbit visits per filter with an 8-point dither in the IR and a 6 point dither in the optical. Our observational plan is to ask for observations ~10-15 x (1+z) days apart and so we will schedule the first two epochs of observations at one time, but make adjust our strategy for the later observations on the basis of the outcome of the first observations. We will observe 3 supernovae in total with 30 orbits in Cycle 31 and 12 in Cycle 32 for host subtraction. However, because of differences in supernovae (redshift, hosts etc) we may not use 10 orbits per SNe. This new submission for GO17840 is for the late time templates, and contains observations for 2 orbits each in F606W, F125W, F140W and F160W. We will update with the details of the timing and sources once they are known. The proposers are both experts in gamma-ray bursts and supernovae and have much experience in studies of these events with HST as well as with Gemini and JWST. Co-PI Andrew Levan has led over 40 successful HST proposals addressing mutliple issues in transient astronomy. Of particular relevance to this proposal are works studying GRB supernovae, including GRB 130427A (Levan et al. 2014) and most recently GRB 221009A with both HST and JWST (Levan et al. 2023). Co-PI Luca Izzo is a highly experienced observational astronomer. He has led HST programmes on Galactic novae and been involved in many more related to gamma-ray bursts and supernovae. He has published extensively on the GRB supernova connection (e.g. Izzo et al. 2019 Nature), and on GRB and supernova host galaxies. The CoI's of the proposal also bring a wealth of experience in GRB observations and have published hundreds of papers in this area over the past decade. We continue to have both the resources and experience to ensure the timely analysis and publication of the results obtained from this project. Stellar Physics and Stellar Types 6 false false false false false false false true PRIMARY 2 6.8 true SUPPORTED EXT-STAR GAMMA RAY BURSTER SUPERNOVA J2000 EXT-STAR GAMMA RAY BURSTER SUPERNOVA J2000 EXT-STAR GAMMA RAY BURSTER SUPERNOVA J2000 EXT-STAR SUPERNOVA J2000 GRB detection at ~ 1.5 < z < 3.0 WFC3/IR Imaging No No F125W WFC3/UVIS Imaging No No F475W WFC3/IR Imaging No No F125W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F140W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F140W WFC3/UVIS Imaging No No F775W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F775W WFC3/IR Imaging No No F160W POS-TARG DITHER DITHER 3 0.099 WFC3-UVIS-DITHER-LINE-3PT false false 0.135 2 3.9 POS-TARG LINE 46.84 3 true POS-TARG DITHER DITHER 4 0.145 WFC3-IR-DITHER-BOX-MIN false 74.653 false 0.365 0.572 2 46.84 POS-TARG LINE 18.528 4 true POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 5 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 6 false The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /private/var/folders/x9/kl1b_86n2jjb48cbc9xt0_dm0000gn/T/OPVisit9174833513719300805.xml 1747815942000 261.02063025164676 (Tic-Visit :proposal-id 17840 :visit-id "A1" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 16:42:41.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1810512 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A1" :obset-id "A1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A1" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2460 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A1" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2440 :al-overhead-at-end 0 :internal-dur-at-end 519 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vA2.xml 1747697060000 261.9599678982362 (Tic-Visit :proposal-id 17840 :visit-id "A2" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:50:39.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1732464 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A2" :obset-id "A2" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A2" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2484 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A2" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2504 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) true 2 1 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /private/var/folders/x9/kl1b_86n2jjb48cbc9xt0_dm0000gn/T/OPVisit13309288235711911823.xml 1759417837000 100.70654220326543 (Tic-Visit :proposal-id 17840 :visit-id "A3" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 16:42:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1810512 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A3" :obset-id "A3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A3" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2460 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2881 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A3" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2440 :al-overhead-at-end 0 :internal-dur-at-end 519 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2881 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vA4.xml 1763507036000 54.153880669417305 (Tic-Visit :proposal-id 17840 :visit-id "A4" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:50:55.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1732464 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A4" :obset-id "A4" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A4" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2484 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2881 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A4" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2504 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2881 :pcs-gap 0 ) true 2 1 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vA5.xml 1763428123000 50.299685981837996 (Tic-Visit :proposal-id 17840 :visit-id "A5" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:51:02.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1810512 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A5" :obset-id "A5" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A5" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2460 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2870 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A5" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2440 :al-overhead-at-end 0 :internal-dur-at-end 519 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2870 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vA6.xml (Tic-Visit :proposal-id 17840 :visit-id "A6" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:51:06.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1732464 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "A6" :obset-id "A6" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "A6" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2484 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17840 :visit-id "A6" :orbit-number 2 :pcs-time 380 :si-vis-utilization 2504 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2867 :pcs-gap 0 ) true 2 1 Awaiting GRB trigger The scheduling data was generated by CASM 34.0. CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vG1.xml 1751800941000 94.2594121931279 (Tic-Visit :proposal-id 17840 :visit-id "G1" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:51:09.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 905248 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "G1" :obset-id "G1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "G1" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2440 :al-overhead-at-end 0 :internal-dur-at-end 728 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2881 :pcs-gap 0 ) true 1 0 Awaiting GRB trigger The scheduling data was generated by CASM 34.0. 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CASM was run in Phase II mode. /Users/levan/Downloads/OP-cache/17840_final-vG3.xml (Tic-Visit :proposal-id 17840 :visit-id "G3" :proposal-version -1 :trans-version "20250929" :date "06-Feb-2026 15:51:39.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17840 :visit-id "G3" :obset-id "G3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17840 :visit-id "G3" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2472 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2870 :pcs-gap 0 ) true 1 0