17837( 7) - 04-Feb-2025 13:51:39 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17837 Version: 7 Check-in Time: 04-Feb-2025 13:51:39 STScI Edit Number: 2 Title Elevating the Scientific Output of JWST by using HST to Examine the Heart of Type Ia Supernova 2021aefx ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Michael Tucker The Ohio State University Y CoI: Dr. James M DerKacy Space Telescope Science Institute N CoI: Prof. Chris Ashall University of Hawaii N CoI: Prof. Benjamin John Shappee University of Hawaii N CoI: Dr. Peter A. Hoeflich Florida State University N CoI: Dr. Melissa Shahbandeh Space Telescope Science Institute N CoI: Dr. Eddie Baron Planetary Science Institute N ------------------------------------------------------------------------------------ Abstract Despite Type Ia supernovae (SNe Ia) remaining a benchmark of precision cosmology, a consensus on how and why some white dwarfs explode as SNe Ia eludes the astronomical community. Photometric observations of SNe Ia at late times measure the conversion efficiency of radioactive decay energy into photons. We request 10 orbits of HST/WFC3 observations in Cycle 31 and 8 orbits in Cycle 32 to observe the normal SN Ia 2021aefx at 750d, 1000d, and 1150d after the explosion in conjunction with already awarded JWST near- and mid-infrared spectra. These complimentary HST and JWST observations provide complete wavelength coverage from 0.4-14 microns spanning years after the explosion. Such data are non-existent in the literature and we do not foresee similar opportunities in the overlapping lifetimes of HST and JWST. Measuring the complete spectral energy distribution at nebular phases allows a direct estimate of the total radioactive decay energy, which in turn depends on the nucleosynthetic yield of the explosion. Many correlations have been proposed for estimating the nucleosynthetic yield of a SN Ia but uncertainties regarding emission in the mid-IR prevented definitive conclusions. With the proposed HST/WFC3 time we can elevate the scientific output from this SN to a level that JWST cannot reach alone, and SN~2021aefx will become a once-in-a-decade event that paves the way for the next generation of SN Ia models. ------------------------------------------------------------------------------------ Observations Description ------------------------ Late-time observations of SN Ia 2021aefx at 750d and 1000d coinciding with JWST observations using F438W, F555W, F600LP, F110W, and F160W filters. ------------------------------------------------------------------------------------ 17837( 7) - 04-Feb-2025 13:51:39 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 2021AEFX EXT-STAR, SUPERNOVA, RA=04H19M53.4000S, J2000 V = 23 +/- 0.1 SUPERNOVA TYPE IA DEC=-54D56'53.09" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17837( 7) - 04-Feb-2025 13:51:39 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.145 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 5 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 17837( 7) - 04-Feb-2025 13:51:39 - [ 4] Visit: 01 (Visit1) Visit Requirements: PCS MODE FINE; BETWEEN 15-JAN-2025:00:00:00 AND 15-FEB-2025:00:00:00 On Hold Comments: Additional Comments: 1150d after peak brightness. Observations in F438W and F555W 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 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F555W 1 800 S NEW OBSET FULL ACQ; NEW S 1C-CTE see below ALIGNMENT; GS ACQ (2562 S) SCENARIO SINGLE; PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F438W FLASH=10 1 400 S PATTERN 4 2 S 1C-CTE see below (5068 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 1 none none none 1 1281.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 2 none none none 1 1281.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 1 none none none 2 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 2 none none none 2 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 3 none none none 3 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 4 none none none 3 1267.0 S S K1C-CTE 17837( 7) - 04-Feb-2025 13:51:39 - [ 5] Visit: 02 (Visit2) Visit Requirements: PCS MODE FINE; BETWEEN 15-JAN-2025:00:00:00 AND 15-FEB-2025:00:00:00 On Hold Comments: Additional Comments: F600LP exposures, 3 orbits 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 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F600LP 1 3000 S GS ACQ SCENARIO SINGLE; S 1C-CTE see below PATTERN 5 1 (3833 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F600LP 1 3600 S POS TARG 0.1, 0.1; S 1C-CTE see below PATTERN 5 2 (3813 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F600LP 1 none none none 1 1281.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F600LP 2 none none none 1 1281.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F600LP 3 none none none 2 1271.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F600LP 1 none none none 2 1271.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F600LP 2 none none none 3 1271.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F600LP 3 none none none 3 1271.0 S S K1C-CTE 17837( 7) - 04-Feb-2025 13:51:39 - [ 6] Visit: 03 (Visit3) Visit Requirements: BETWEEN 15-JAN-2025:00:00:00 AND 15-FEB-2025:00:00:00 On Hold Comments: Additional Comments: Additional F555W and F600LP exposures 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 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F600LP 1 3000 S POS TARG 0.1, -0.1; GS S 1C-CTE see below ACQ SCENARIO SINGLE; (2562 S) PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F555W 1 3000 S POS TARG 0.1, 0.1; S 1C-CTE see below PATTERN 2 2 (2542 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F600LP 1 none none none 1 1281.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F600LP 2 none none none 1 1281.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F555W 1 none none none 2 1271.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F555W 2 none none none 2 1271.0 S S K1C-CTE 17837( 7) - 04-Feb-2025 13:51:39 - [ 7] Visit: 51 (Visit1 - repeat) Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: 1150d after peak brightness. Observations in F438W and F555W 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 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F555W 1 800 S NEW OBSET FULL ACQ; NEW S 1C-CTE see below ALIGNMENT; GS ACQ (2562 S) SCENARIO SINGLE; PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F438W FLASH=10 1 400 S PATTERN 4 2 S 1C-CTE see below (5068 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 1 none none none 1 1281.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 2 none none none 1 1281.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 1 none none none 2 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 2 none none none 2 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 3 none none none 3 1267.0 S S K1C-CTE 2021AEFX 2 WFC3/UVI ACCUM UVIS2-C1 F438W 4 none none none 3 1267.0 S S K1C-CTE 17837( 7) - 04-Feb-2025 13:51:39 - [ 8] Visit: 53 (Visit3 - partial repeat) Visit Requirements: On Hold Comments: Additional Comments: Additional F555W and F600LP exposures 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 2021AEFX WFC3/UVI ACCUM UVIS2-C1K F555W 1 3000 S POS TARG 0.1, 0.1; S 1C-CTE see below PATTERN 2 1 (2542 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 | ------------------------------------------------------------------------------------------------------------------------------------ 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 1 none none none 1 1271.0 S S K1C-CTE 2021AEFX 1 WFC3/UVI ACCUM UVIS2-C1 F555W 2 none none none 1 1271.0 S S K1C-CTE 17837( 7) - 04-Feb-2025 13:51:39 - [ 9] Summary Form for Proposal 17837 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-C1K1C-CTE ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 15-JAN-2025:00:00:00 AND 15-FEB-2025:00:00:00, GS ACQ SCENARIO SINGLE, NEW ALIGNMENT, NEW OBSET FULL ACQ, PATTERN 2 1, PATTERN 2 2, PATTERN 4 2, PATTERN 5 1, PATTERN 5 2, PCS MODE FINE, POS TARG 0.1, -0.1, POS TARG 0.1, 0.1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F438W, F555W, F600LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names 2021AEFX ------------------------------------------------------------------------------------------------------------------------------------