15205( 3) - 05-Dec-2018 18:57:38 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15205 Version: 3 Check-in Time: 05-Dec-2018 18:57:38 STScI Edit Number: 1 Title Left Behind: A Bound Remnant from a White Dwarf Supernova? ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Saurabh W. Jha Rutgers the State University of New Jersey Y CoI: Dr. Curtis McCully Las Cumbres Observatory Global Telescope N Network CoI: Prof. Ryan Foley University of California - Santa Cruz N CoI: Ms. Yssavo Camacho Rutgers the State University of New Jersey N ------------------------------------------------------------------------------------ Abstract Type Ia supernovae (SN Ia) have enormous importance to cosmology and astrophysics, but their progenitors and explosion mechanisms are not understood in detail. Recently, observations and theoretical models have suggested that not all thermonuclear white-dwarf supernova explosions are normal SN Ia. In particular, type Iax supernovae (peculiar cousins to SN Ia), are thought to be exploding white dwarfs that are not completely disrupted, leaving behind a bound remnant. In deep and serendipitous HST pre-explosion data, we have discovered a luminous, blue progenitor system for the type Iax SN 2012Z in NGC 1309, which we interpret as a helium-star donor to the exploding white dwarf. HST observations of SN 2012Z in 2016, when the supernova light was expected to have faded away, still show a source at the location, as expected in our model where the pre-explosion flux was coming from the companion. However, the 2016 data also show a surprise: an excess flux compared to the progenitor system. Our proposed observations here will help unravel the mystery of that excess flux: is it from the bound ex-white dwarf remnant? Or is it from the shocked companion star that has been bombarded by supernova ejecta? Either of these possibilities would provide key new evidence as to the nature of these white dwarf supernovae. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to obtain late-time optical ACS/WFC BVI images at the location of SN 2012Z in NGC 1309 to look for further changes in the system. We have constructed our proposed observations to match the ACS/WFC data from Cycle 22, which in turn corresponded to the pre-explosion images and photometry of S1 in terms of filters and depth. Our best measurement of any changes from the pre-explosion and Cycle 22 images will come from image-subtraction analysis. We will use dithering and subsampling to improve the spatial resolution of the ACS images, as we did in our previous observations. To measure a meaningful change in the system, we will aim for S/N ~ 10 at the brightness of the progenitor S1 in the new F435W and F555W images, and S/N ~ 8 in F814W. These choices match the depth achieved in the Cycle 22 images from 2016. Based on the ACS/WFC ETC, using a 0.15 arcsec (3 pixel) aperture radius, 15205( 3) - 05-Dec-2018 18:57:38 - [ 2] we require 9500 sec of exposure in F435W, 13500 sec in F555W, and 14100 sec in F814W. With overheads, this requires 14 orbits. Given the expected ~years timescale for changes in the system, we propose these data for the nominal Cycle 26 period (late 2018/early 2019, at approximately +2500 days. As a small program, we are proposing for this time now in Cycle 25, as required. ------------------------------------------------------------------------------------ 15205( 3) - 05-Dec-2018 18:57:38 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN-2012Z EXT-STAR, SUPERNOVA RA=03H22M5.3500S, J2000 V = 27.6 +/- 2.0 DEC=-15D23'15.60" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 15205( 3) - 05-Dec-2018 18:57:38 - [ 4] Visit: 01 Visit Requirements: ORIENT 240D TO 80 D; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.000, 0.000 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.247, 0.094 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.247, 0.094 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.000, 0.000 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.000, 0.000 (1329 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.247, 0.094 (1329 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-2012Z 1 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 3 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 4 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 5 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A SN-2012Z 6 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 5] Visit: 02 Visit Requirements: SAME ORIENT AS 01; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.124, 0.232 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG -0.124, 0.138 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG -0.124, 0.138 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.124, 0.232 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.124, 0.232 (1329 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG -0.124, 0.138 (1329 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-2012Z 1 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 3 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 4 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 5 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A SN-2012Z 6 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 6] Visit: 03 Visit Requirements: SAME ORIENT AS 01; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.000, 0.000 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.247, 0.094 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.247, 0.094 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.000, 0.000 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.000, 0.000 (1329 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.247, 0.094 (1329 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-2012Z 1 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 3 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 4 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 5 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A SN-2012Z 6 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 7] Visit: 04 Visit Requirements: SAME ORIENT AS 01; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG 0.124, 0.232 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F435W 1 1252 S POS TARG -0.124, 0.138 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG -0.124, 0.138 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1338 S POS TARG 0.124, 0.232 (1338 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG 0.124, 0.232 (1329 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1329 S POS TARG -0.124, 0.138 (1329 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-2012Z 1 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F435W none none none none 1 N/A SN-2012Z 3 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 4 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 5 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A SN-2012Z 6 ACS/WFC ACCUM WFC1 F555W none none none none 3 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 8] Visit: 05 Visit Requirements: ORIENT 240D TO 80 D; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F555W 1 1252 S POS TARG 0.000, 0.000 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1252 S POS TARG 0.247, 0.094 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1329 S POS TARG 0.247, 0.094 (1329 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN-2012Z ACS/WFC ACCUM WFC1 F814W 1 1329 S POS TARG 0.000, 0.000 (1329 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-2012Z 1 ACS/WFC ACCUM WFC1 F555W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F555W none none none none 1 N/A SN-2012Z 3 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A SN-2012Z 4 ACS/WFC ACCUM WFC1 F814W none none none none 2 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 9] Visit: 55 Visit Requirements: ORIENT 240D TO 80 D; AFTER 01-JUL-2018:00:00:00 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-2012Z ACS/WFC ACCUM WFC1 F555W 1 1252 S POS TARG 0.000, 0.000 (1252 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z ACS/WFC ACCUM WFC1 F555W 1 1252 S POS TARG 0.247, 0.094 (1252 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-2012Z 1 ACS/WFC ACCUM WFC1 F555W none none none none 1 N/A SN-2012Z 2 ACS/WFC ACCUM WFC1 F555W none none none none 1 N/A 15205( 3) - 05-Dec-2018 18:57:38 - [ 10] Summary Form for Proposal 15205 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01-JUL-2018:00:00:00, ORIENT 240D TO 80 D, POS TARG -0.124, 0.138, POS TARG 0.000, 0.000, POS TARG 0.124, 0.232, POS TARG 0.247, 0.094, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F435W, F555W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN-2012Z ------------------------------------------------------------------------------------------------------------------------------------