16884( 3) - 23-Nov-2021 14:46:19 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16884 Version: 3 Check-in Time: 23-Nov-2021 14:46:19 STScI Edit Number: 1 Title Do subluminous Type Ia supernovae experience a near-infrared plateau? ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Or Graur University of Portsmouth Y CoI: Dr. Ken Shen University of California - Berkeley N CoI: Dr. Ivo Rolf Seitenzahl University of New South Wales N CoI: Dr. Robert Fisher University of Massachusetts Dartmouth N CoI: Dr. Dale Andrew Howell Las Cumbres Observatory Global Telescope N Network CoI: Dr. Curtis McCully Las Cumbres Observatory Global Telescope N Network CoI: Griffin Hosseinzadeh University of Arizona N CoI: Dr. Michael Shara American Museum of Natural History N CoI: Dr. David R. Zurek American Museum of Natural History N CoI: Dr. Saurabh W. Jha Rutgers the State University of New Jersey N CoI: Dr. Lluis Galbany Institute of Space Sciences (CSIC-IEEC) N CoI: Dr. Adam Riess The Johns Hopkins University N CoI: Dr. Armin Rest Space Telescope Science Institute N CoI: Dr. Wolfgang E Kerzendorf Michigan State University N CoI: Dr. Andrew Giles Fullard Michigan State University N ------------------------------------------------------------------------------------ Abstract We ask for 4 WFC3 orbits to observe the subluminous 1991bg-like Type Ia supernova (SN Ia) SN 2021qvv when it is 150-250 days past maximum light. With observations in F125W (J), F160W (H), and F350LP (optical) in each of four visits, we will determine whether this SN Ia subtype undergoes a similar near-infrared (NIR) plateau as the one recently discovered in so-called "normal" SNe Ia. The latter have long been used as standard candles in cosmology, yet the nature of their progenitors and explosion mechanism remains elusive. The abundance of SN Ia subtypes, including 1991bg-like SNe Ia, only complicates matters. It is still unclear whether several (or all) SN Ia subtypes share the same progenitor and explosion method as normal SNe Ia, or whether each subtype originates in a different type of star and explosion physics. The first option ties into the nagging question of how standard SNe Ia really are as standard candles. Revealing the progenitors of normal SNe Ia and the other SN Ia subtypes would go some way to answering this question. The recently discovered NIR plateau at 150-500 days offers a new way to constrain the progenitors and explosion physics. In normal SNe Ia, this plateau could be a third NIR maximum, similar to the second NIR maximum seen shortly after the first peak. These additional peaks could be due to the recombination of iron in the expanding ejecta. These secondary NIR peaks are not seen in 1991bg-like SNe Ia, a fact used to constrain the mass, temperature, and chemical composition of the progenitor. The presence or absence of the late-time NIR plateau in 1991bg-like SNe would place further constraints on the progenitor and the recombination wave model. ------------------------------------------------------------------------------------ 16884( 3) - 23-Nov-2021 14:46:19 - [ 2] Observations Description ------------------------ In this program, we will be observing a 1991bg-like supernova called SN 2021qvv. In each visit, one orbit will be split between F350LP, F125W, and F160W, with most of the time spent on the near-IR filters. The first visit is set to occur sometime in the first half of December, as I assume that's the earliest date we could schedule it. The next visit should occur 25-35 days after the first visit. This will also be the cadence for visits 3 and 4. The timing of visit 4 will be flexible. Once visits 1 and 2 are taken, we will analyze the data, locate the supernova, and decide whether we underestimated the background light from the host galaxy. If that is the case, visit 4 will be moved to the end of Cycle 30, when the supernova has faded away, and be used as a template to subtract from visits 1-3. This will allow us to subtract the galaxy and isolate the supernova. Throughout the program, we may ask to remove certain filters or change exposure times, based on our ongoing analysis of the incoming data. We will always allow plenty of time for such changes to be scheduled. ------------------------------------------------------------------------------------ 16884( 3) - 23-Nov-2021 14:46:19 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2021QVV EXT-STAR, SUPERNOVA RA=12H28M2.9800S, J2000 V = 19 TYPE IA DEC=+09D48'9.90" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 16884( 3) - 23-Nov-2021 14:46:19 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.636 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 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 ------------------------------------------------------------------------------------------------------------------------------------ 16884( 3) - 23-Nov-2021 14:46:19 - [ 5] Visit: 01 (170 days) Visit Requirements: BETWEEN 10-DEC-2021:00:00:00 AND 20-DEC-2021:00:00:00 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 SN2021QVV WFC3/UVI ACCUM UVIS1-2K2 F350LP FLASH=15 1 20 S (60 PATTERN 2 1 S A-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2021QVV WFC3/IR MULTIAC IR-UVIS F125W NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 2-3 CUM (1005.874 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2021QVV WFC3/IR MULTIAC IR-UVIS F160W NSAMP=10, SAMP-SEQ=SPARS50 1 DEF CUM (905.873 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 1 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 2 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 3 none none none 1 N/A S 2A-SUB SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 1 none none none 1 N/A CUM SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 2 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 1 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 2 none none none 1 N/A CUM 16884( 3) - 23-Nov-2021 14:46:19 - [ 6] Visit: 02 (195 days) Visit Requirements: AFTER 01 BY 26 D TO 35 D 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 SN2021QVV WFC3/UVI ACCUM UVIS1-2K2 F350LP FLASH=15 1 20 S (60 PATTERN 2 1 S A-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2021QVV WFC3/IR MULTIAC IR-UVIS F125W NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 2-3 CUM (1005.874 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2021QVV WFC3/IR MULTIAC IR-UVIS F160W NSAMP=10, SAMP-SEQ=SPARS50 1 DEF CUM (905.873 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 1 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 2 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 3 none none none 1 N/A S 2A-SUB SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 1 none none none 1 N/A CUM SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 2 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 1 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 2 none none none 1 N/A CUM 16884( 3) - 23-Nov-2021 14:46:19 - [ 7] Visit: 03 (220 days) Visit Requirements: AFTER 02 BY 26 D TO 35 D 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 SN2021QVV WFC3/UVI ACCUM UVIS1-2K2 F350LP FLASH=15 1 20 S (60 PATTERN 2 1 S A-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2021QVV WFC3/IR MULTIAC IR-UVIS F125W NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 2-3 CUM (1005.874 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2021QVV WFC3/IR MULTIAC IR-UVIS F160W NSAMP=10, SAMP-SEQ=SPARS50 1 DEF CUM (905.873 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 1 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 2 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 3 none none none 1 N/A S 2A-SUB SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 1 none none none 1 N/A CUM SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 2 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 1 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 2 none none none 1 N/A CUM 16884( 3) - 23-Nov-2021 14:46:19 - [ 8] Visit: 04 (245 days) Visit Requirements: AFTER 03 BY 26 D TO 35 D 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 SN2021QVV WFC3/UVI ACCUM UVIS1-2K2 F350LP FLASH=15 1 20 S (60 PATTERN 2 1 S A-SUB S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2021QVV WFC3/IR MULTIAC IR-UVIS F125W NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 2-3 CUM (1005.874 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2021QVV WFC3/IR MULTIAC IR-UVIS F160W NSAMP=10, SAMP-SEQ=SPARS50 1 DEF CUM (905.873 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 1 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 2 none none none 1 N/A S 2A-SUB SN2021QVV 1 WFC3/UVI ACCUM UVIS1-2K F350LP 3 none none none 1 N/A S 2A-SUB SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 1 none none none 1 N/A CUM SN2021QVV 2 WFC3/IR MULTIAC IR-UVIS F125W 2 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 1 none none none 1 N/A CUM SN2021QVV 3 WFC3/IR MULTIAC IR-UVIS F160W 2 none none none 1 N/A CUM 16884( 3) - 23-Nov-2021 14:46:19 - [ 9] Summary Form for Proposal 16884 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-UVIS, UVIS1-2K2A-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=15, NSAMP=10, NSAMP=11, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 26 D TO 35 D, AFTER 02 BY 26 D TO 35 D, AFTER 03 BY 26 D TO 35 D, BETWEEN 10-DEC-2021:00:00:00 AND 20-DEC-2021:00:00:00, PATTERN 1 2-3, PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F125W, F160W, F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2021QVV ------------------------------------------------------------------------------------------------------------------------------------