18214( 13) - 04-Nov-2025 23:36:56 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 18214 Version: 13 Check-in Time: 04-Nov-2025 23:36:56 STScI Edit Number: 6 Title Spectral Synergy of SN2023ixf: A unique insight into a nearby, radio- bright core-collapse supernovae. ------------------------------------------------------------------------------------ Type Cycle GO/DD 33 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Conor Ransome University of Arizona Y CoI: Dr. Joanne Pledger University of Central Lancashire N CoI: Dr. Megan Argo University of Central Lancashire N CoI: Diane Swan University of Central Lancashire N ------------------------------------------------------------------------------------ Abstract SN2023ixf has been one of the most studied core collapse supernova, although it has faded in the optical domain, the transient has become bright in the radio. A recent re-brightening event offers a unique opportunity to extend the multi-domain observations of this object in the optical and radio. There is a Rapid Response Time proposal was granted using eMERLIN VLBI to make a series of 5 observations, of which the first two have been completed with a clear detection of the order of 1 mJy. However, the insights provided by the UV and optical spectra will provide a detailed analysis of the CSM conditions and shockwave characteristics. HST remains the only instrument capable of providing the spectra for SN2023ixf at this late stage, as we require the UV, and M101 is a Spring target. The combination of data in these domains will provide a clear understanding of CSM properties at the current shockwave radius and a direct insight into the progenitor history. The interaction of the CSM properties and the shockwave, creating the synchrotron radio emission, will constrain the power law arguments related to CSM density changes with time and distance. In addition, provide a test for recent considerations of alternatives to CSM density as a the sole cause of deviation from power law models in the radio domain. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program is to observe SN 2023ixf from the optival to the FUV. The first epoch is 2 orbits, and will be scheduled as a single visit before Nov 8 2025. The subsequent epochs (also 2 orbits each), will repeat the same setup, with the second epoch taking place between 10-15 days after the 1st epoch. The 3rd epoch being 10-15 days after the 2nd epoch. However, if we do not see significant evolution, we will forego the third epoch, unless there is unexpected evolution in our radio observations. The faintest SN 2023ixf will be at this phase is V=23 mag. . ------------------------------------------------------------------------------------ 18214( 13) - 04-Nov-2025 23:36:56 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN-2023IXF STAR, CIRCUMSTELLAR RA=14H03M38.5628S, J2000 V = 23 +/- 0.1 MATTER, SUPERNOVA, DEC=+54D18'41.94" SUPERNOVA TYPE II Reference Frame: ICRS Extended: NO Comments: This object was generated by the targetselector and retrieved from the NED database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN23IXF-OFFS EXT-STAR, K V-IV RA=14H03M39.8499S +/- 0.03", J2000 V = 20.5 ET-LEGACY531 DEC=+54D18'6.99" +/- 0.03" 3 Reference Frame: ICRS Comments: g=20.48, r=20.43, z=20.39 ------------------------------------------------------------------------------------------------------------------------------------ 18214( 13) - 04-Nov-2025 23:36:56 - [ 3] Visit: 01 (Epoch 1 - CCD) Visit Requirements: BEFORE 24-NOV-2025:00:00:00; GROUP 01, 02 WITHIN 24H; TOO RESPONSE TIME 3.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN23IXF-OFF STIS/CCD ACQ F28X50LP MIRROR 1 60 S (60 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 CCDFLAT STIS/CCD ACCUM 52X0.5 G750M 6768 2 DEF (0 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/CCD ACCUM 52X0.5E1 G750M 6581 1 650 S see below (664 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/CCD ACCUM 52X0.5E1 G750M 6581 1 650 S see below (664 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 CCDFLAT STIS/CCD ACCUM 52X0.5 G750M 6768 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN23IXF-OFFSET-LEGA 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A CY5313 CCDFLAT 2 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 1 none 1 N/A CCDFLAT 2 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 2 none 1 N/A SN-2023IXF 3 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 1 1 332.0 S SN-2023IXF 3 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 2 1 332.0 S SN-2023IXF 4 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 1 1 332.0 S SN-2023IXF 4 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 2 1 332.0 S CCDFLAT 5 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 1 none 1 N/A CCDFLAT 5 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 2 none 1 N/A 18214( 13) - 04-Nov-2025 23:36:56 - [ 4] Visit: 02 (Epoch 1 - MAMA) Visit Requirements: BEFORE 24-NOV-2025:00:00:00; TOO RESPONSE TIME 3.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN23IXF-OFF STIS/CCD ACQ F28X50LP MIRROR 1 60 S (60 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/NUV TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=555 1 1110 S -MAMA G (1110 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/NUV TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=555 1 1110 S -MAMA G (1110 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=400 1 800 S (800 -MAMA G 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN23IXF-OFFSET-LEGA 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A CY5313 SN-2023IXF 2 STIS/NUV TIME-TA 52X0.5 G230L 2376 none none none none 1 N/A -MAMA G SN-2023IXF 3 STIS/NUV TIME-TA 52X0.5 G230L 2376 none none none none 2 N/A -MAMA G SN-2023IXF 4 STIS/FUV TIME-TA 52X0.5 G140L 1425 none none none none 2 N/A -MAMA G 18214( 13) - 04-Nov-2025 23:36:56 - [ 5] Visit: 03 (Epoch 2 - CCD) Visit Requirements: AFTER 02 BY 10 D TO 15 D; GROUP 03, 04 WITHIN 24H; TOO RESPONSE TIME 3.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN23IXF-OFF STIS/CCD ACQ F28X50LP MIRROR 1 60 S (60 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 CCDFLAT STIS/CCD ACCUM 52X0.5 G750M 6768 2 DEF (0 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/CCD ACCUM 52X0.5E1 G750M 6581 1 650 S see below (664 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/CCD ACCUM 52X0.5E1 G750M 6581 1 650 S see below (664 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 CCDFLAT STIS/CCD ACCUM 52X0.5 G750M 6768 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN23IXF-OFFSET-LEGA 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A CY5313 CCDFLAT 2 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 1 none 1 N/A CCDFLAT 2 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 2 none 1 N/A SN-2023IXF 3 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 1 1 332.0 S SN-2023IXF 3 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 2 1 332.0 S SN-2023IXF 4 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 1 1 332.0 S SN-2023IXF 4 STIS/CCD ACCUM 52X0.5E1 G750M 6581 none none none 2 1 332.0 S CCDFLAT 5 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 1 none 1 N/A CCDFLAT 5 STIS/CCD ACCUM 52X0.5 G750M 6768 none none 2 none 1 N/A 18214( 13) - 04-Nov-2025 23:36:56 - [ 6] Visit: 04 (Epoch 2 - MAMA) Visit Requirements: TOO RESPONSE TIME 3.0D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SN23IXF-OFF STIS/CCD ACQ F28X50LP MIRROR 1 60 S (60 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/NUV TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=555 1 1110 S -MAMA G (1110 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/NUV TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=555 1 1110 S -MAMA G (1110 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/FUV TIME-TA 52X0.5 G140L 1425 BUFFER-TIME=400 1 800 S (800 -MAMA G 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN23IXF-OFFSET-LEGA 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A CY5313 SN-2023IXF 2 STIS/NUV TIME-TA 52X0.5 G230L 2376 none none none none 1 N/A -MAMA G SN-2023IXF 3 STIS/NUV TIME-TA 52X0.5 G230L 2376 none none none none 2 N/A -MAMA G SN-2023IXF 4 STIS/FUV TIME-TA 52X0.5 G140L 1425 none none none none 2 N/A -MAMA G 18214( 13) - 04-Nov-2025 23:36:56 - [ 7] Summary Form for Proposal 18214 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.5, 52X0.5E1, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=400, BUFFER-TIME=555 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 02 BY 10 D TO 15 D, BEFORE 24-NOV-2025:00:00:00, GROUP 01, 02 WITHIN 24H, GROUP 03, 04 WITHIN 24H, TOO RESPONSE TIME 3.0D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, G750M, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names CCDFLAT, SN-2023IXF, SN23IXF-OFFSET-LEGACY5313 ------------------------------------------------------------------------------------------------------------------------------------