17772( 7) - 26-Mar-2025 18:08:57 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17772 Version: 7 Check-in Time: 26-Mar-2025 18:08:57 STScI Edit Number: 3 Title Probing Red Supergiant Mass Loss 100-200 Years Before Explosion using UV Spectra of the Extraordinary SN 2023ixf ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Kyra Azalee Bostroem University of Arizona Y CoI: Prof. David J. Sand University of Arizona N CoI: Dr. Stefano Valenti University of California - Davis N CoI: Dr. Jennifer Andrews NOIRLab - Gemini North (HI) N CoI: Dr. Manisha Shrestha University of Arizona N CoI: Dr. Saurabh W. Jha Rutgers the State University of New Jersey N CoI: Dr. Michael Jon Lundquist California Association for Research in N Astronomy (CARA) CoI: Jeniveve Pearson University of Arizona N CoI: Mr. Nicolas Eduardo Meza Retamal University of California - Davis N CoI: Dr. Jacob Jencson California Institute of Technology N CoI: Emily Hoang University of California - Davis N CoI: Daryl Janzen University of Saskatchewan N CoI: Dr. Aravind Pazhayath Ravi University of California - Davis N CoI: Ms. Darshana Mehta University of California - Davis N CoI: Mr. Yize Dong Center for Astrophysics | Harvard & N Smithsonian CoI: Prof. Griffin Hosseinzadeh University of California - San Diego N ------------------------------------------------------------------------------------ Abstract Mass loss in red supergiants is currently a topic of much debate, with proposed rates between 10^-7 and 10^-1 solar masses per year and hints of periods of enhanced mass loss which may be more prevalent as the red supergiant approaches explosion. However, observations of red supergiants tend to probe thousand of years prior to explosion while optical observations of the supernova probe the final 5 years and are only sensitive to the highest levels of mass loss. About 50 days after explosion, Lyman-alpha and Mg II emission lines form when there is interaction between the supernova ejecta and circumstellar medium, even when the optical is indistinguishable from a non-interacting supernova. These lines are extremely sensitive to all levels of circumstellar interaction, however, as the UV is very faint, obtaining these observations requires a very nearby supernova. On May 19, 2023, SN 2023ixf was discovered at 6.9 Mpc. Early spectra showed narrow, high-ionization emission lines characteristic of dense, confined circumstellar material which disappeared within a week. With a non-detection less than 24 hours before and rapid classification, this very nearby supernova was observed in exquisite detail from gamma rays to radio, including with HST in the UV starting just 3.5d after explosion and continuing through ~300d after explosion. With these observations, we can map out the mass-loss history of the red supergiant progenitor out to 75 years before explosion. Here, we ask for two epochs of FUV and NUV spectra, taking our mass-loss history of the progenitor star to ~200 years before explosion, giving us an unprecedented and detailed view of mass loss in a red supergiant. 17772( 7) - 26-Mar-2025 18:08:57 - [ 2] ------------------------------------------------------------------------------------ Observations Description ------------------------ This program is to observe SN 2023ixf in the FUV and NUV at two epochs. The first epoch is 3 orbits (1 FUV, 2 NUV) and will be scheduled as a single visit before Mar 1, 2025. The faintest SN 2023ixf will be at this phase is V=21.5 The epoch will be broken into a FUV visit (2 orbits) and an NUV visit (5 orbits) scheduled within a week of each other. This epoch will occur after Mar 1, 2025 and after visit 1 by 4 months. The faintest SN 2023ixf will be at this phase is V=23 ------------------------------------------------------------------------------------ 17772( 7) - 26-Mar-2025 18:08:57 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN-2023IXF EXT-STAR, SUPERNOVA, RA=14H03M38.5620S, J2000 V = 23 SUPERNOVA TYPE II DEC=+54D18'41.94" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD 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 ------------------------------------------------------------------------------------------------------------------------------------ 17772( 7) - 26-Mar-2025 18:08:57 - [ 4] Visit: 01 (Epoch 1) Visit Requirements: BEFORE 01-MAR-2025:00:00:00 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 SN-2023IXF STIS/CCD ACQ 50CCD MIRROR 1 55 S (55 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/NUV ACCUM 52X0.5 G230L 2376 1 1934 S -MAMA (1934 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/NUV ACCUM 52X0.5 G230L 2376 1 2670 S -MAMA (2670 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/FUV ACCUM 52X0.5 G140L 1425 1 2628 S -MAMA (2628 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-2023IXF 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A SN-2023IXF 2 STIS/NUV ACCUM 52X0.5 G230L 2376 none none none none 1 N/A -MAMA SN-2023IXF 3 STIS/NUV ACCUM 52X0.5 G230L 2376 none none none none 2 N/A -MAMA SN-2023IXF 4 STIS/FUV ACCUM 52X0.5 G140L 1425 none none none none 3 N/A -MAMA 17772( 7) - 26-Mar-2025 18:08:57 - [ 5] Visit: 03 (Epoch 2 NUV-offset) Visit Requirements: AFTER 05 BY 100 D TO 365 D; BETWEEN 01-MAR-2025:00:00:00 AND 01-JUL-2025:00:00:00; GROUP 03, 04 WITHIN 7D 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 50 S (50 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/NUV ACCUM 52X0.2 G230L 2376 1 2025 S -MAMA (2025 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/NUV ACCUM 52X0.2 G230L 2376 1 2670 S -MAMA (2670 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/NUV ACCUM 52X0.2 G230L 2376 1 2670 S -MAMA (2670 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-2023IXF STIS/NUV ACCUM 52X0.2 G230L 2376 1 2670 S -MAMA (2670 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-2023IXF STIS/NUV ACCUM 52X0.2 G230L 2376 1 2670 S -MAMA (2670 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 ACCUM 52X0.2 G230L 2376 none none none none 1 N/A -MAMA SN-2023IXF 3 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 2 N/A -MAMA SN-2023IXF 4 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 3 N/A -MAMA SN-2023IXF 5 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 4 N/A -MAMA SN-2023IXF 6 STIS/NUV ACCUM 52X0.2 G230L 2376 none none none none 5 N/A -MAMA 17772( 7) - 26-Mar-2025 18:08:57 - [ 6] Visit: 04 (Epoch 2 FUV - offset) Visit Requirements: AFTER 05 BY 100 D TO 365 D; BETWEEN 01-MAR-2025:00:00:00 AND 01-JUL-2025:00:00:00; GROUP 04, 03 WITHIN 7D 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 50 S (50 SET-LEGACY5 S) 313 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/FUV ACCUM 52X0.2 G140L 1425 1 2025 S -MAMA (2025 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/FUV ACCUM 52X0.2 G140L 1425 1 2670 S -MAMA (2670 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/FUV ACCUM 52X0.2 G140L 1425 none none none none 1 N/A -MAMA SN-2023IXF 3 STIS/FUV ACCUM 52X0.2 G140L 1425 none none none none 2 N/A -MAMA 17772( 7) - 26-Mar-2025 18:08:57 - [ 7] Visit: 05 (Epoch 1) Visit Requirements: BEFORE 01-MAR-2025:00:00:00 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 SN-2023IXF STIS/CCD ACQ 50CCD MIRROR 1 55 S (55 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2023IXF STIS/NUV ACCUM 52X0.5 G230L 2376 1 1934 S -MAMA (1934 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2023IXF STIS/NUV ACCUM 52X0.5 G230L 2376 1 2670 S -MAMA (2670 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2023IXF STIS/FUV ACCUM 52X0.5 G140L 1425 1 2628 S -MAMA (2628 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN-2023IXF 1 STIS/CCD ACQ 50CCD MIRROR none none none none 1 N/A SN-2023IXF 2 STIS/NUV ACCUM 52X0.5 G230L 2376 none none none none 1 N/A -MAMA SN-2023IXF 3 STIS/NUV ACCUM 52X0.5 G230L 2376 none none none none 2 N/A -MAMA SN-2023IXF 4 STIS/FUV ACCUM 52X0.5 G140L 1425 none none none none 3 N/A -MAMA 17772( 7) - 26-Mar-2025 18:08:57 - [ 8] Summary Form for Proposal 17772 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 50CCD, 52X0.2, 52X0.5, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA, STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 05 BY 100 D TO 365 D, BEFORE 01-MAR-2025:00:00:00, BETWEEN 01-MAR-2025:00:00:00 AND 01-JUL-2025:00:00:00, GROUP 03, 04 WITHIN 7D, GROUP 04, 03 WITHIN 7D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, G230L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN-2023IXF, SN23IXF-OFFSET-LEGACY5313 ------------------------------------------------------------------------------------------------------------------------------------