16078( 4) - 20-Mar-2020 21:54:05 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16078 Version: 4 Check-in Time: 20-Mar-2020 21:54:05 STScI Edit Number: 0 Title Late Time Photometry of a Type Ia Supernova with an Early, Red Light Curve Excess ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. David J. Sand University of Arizona Y CoI: Maria Drout University of Toronto N CoI: Dr. Dae-Sik Moon University of Toronto N CoI: Dr. Stefano Valenti University of California - Davis N CoI: Rachael C Amaro University of Arizona N CoI: Chris Ni University of Toronto N ------------------------------------------------------------------------------------ Abstract Type Ia supernovae (SNe) are essential cosmological distance indicators, but despite their intense study we still do not definitively know their progenitor systems or how exactly the carbon oxygen white dwarf ultimately explodes. We propose to observe the fading optical+NIR light of the nearby SN 2018aoz, which displayed an early, red light curve excess or `bump', but was an otherwise normal SN Ia. This excess may point to a so-called double detonation explosion, shocking of a companion star by the SN ejecta, or an unusual nickel distribution -- or a combination of several of these possibilities. Very late time SN Ia light curves -- only possible with HST -- can distinguish between progenitor and explosion scenarios by constraining the abundance of 57Co and thus can corroborate (or reject) the light curve signatures seen at early times. These observations are essential for building up a clear and comprehensive picture of this otherwise normal SN Ia; similar early time light curve features have only been observable within the last few years, and none with the dramatic early red feature that we witness in SN 2018aoz. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to observe the late-time light curve of the Type Ia supernova (SN Ia) SN 2018aoz in one visit with WFC3. In four orbits, we will use F438W, F555W, F600LP, and F110W. For the UVIS filters, a WFC3-UVIS-DITHER-LINE-3PT dithering pattern is used, and for the F110W filter, we use the WFC3-IR-DITHER-LINE pattern. ------------------------------------------------------------------------------------ 16078( 4) - 20-Mar-2020 21:54:05 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2018AOZ STAR, SUPERNOVA TYPE IA RA=11H51M1.7900S, J2000 V = 26.5 +/- 0.5 DEC=-28D44'38.40" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 16078( 4) - 20-Mar-2020 21:54:05 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.605 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 41.788 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16078( 4) - 20-Mar-2020 21:54:05 - [ 4] Visit: 01 (visit1) Visit Requirements: BETWEEN 01-JUN-2020:00:00:00 AND 30-AUG-2020:00:00:00; GROUP 01, 02, 03 WITHIN 7D On Hold Comments: Additional Comments: Observations of SN2018aoz. We'll take images in the F438W, F555W, F600LP, and F110W filters. 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 SN2018AOZ WFC3/UVI ACCUM UVIS2 F438W FLASH=9 1 465 S PATTERN 1 1 S (1395 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2018AOZ WFC3/UVI ACCUM UVIS2 F438W FLASH=9 1 500 S PATTERN 1 2 S see below (1601 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2018AOZ WFC3/UVI ACCUM UVIS2 F600LP 1 580 S PATTERN 1 3 S (1740 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F438W 1 none none none 1 N/A S SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F438W 2 none none none 1 N/A S SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F438W 3 none none none 1 N/A S SN2018AOZ 2 WFC3/UVI ACCUM UVIS2 F438W 1 none none none 1 450.0 S S SN2018AOZ 2 WFC3/UVI ACCUM UVIS2 F438W 2 none none none 1 443.0 S S SN2018AOZ 2 WFC3/UVI ACCUM UVIS2 F438W 3 none none none 2 708.0 S S SN2018AOZ 3 WFC3/UVI ACCUM UVIS2 F600LP 1 none none none 2 N/A S SN2018AOZ 3 WFC3/UVI ACCUM UVIS2 F600LP 2 none none none 2 N/A S SN2018AOZ 3 WFC3/UVI ACCUM UVIS2 F600LP 3 none none none 2 N/A S 16078( 4) - 20-Mar-2020 21:54:05 - [ 5] Visit: 02 (visit2) Visit Requirements: GROUP 02, 01, 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 SN2018AOZ WFC3/IR MULTIAC IR-UVIS F110W NSAMP=10, SAMP-SEQ=STEP100 1 DEF PATTERN 2 1 CUM (1197.695 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2018AOZ WFC3/IR MULTIAC IR-UVIS F110W NSAMP=10, SAMP-SEQ=STEP100 1 DEF PATTERN 2 2 CUM (1197.695 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2018AOZ 1 WFC3/IR MULTIAC IR-UVIS F110W 1 none none none 1 N/A CUM SN2018AOZ 1 WFC3/IR MULTIAC IR-UVIS F110W 2 none none none 1 N/A CUM SN2018AOZ 1 WFC3/IR MULTIAC IR-UVIS F110W 3 none none none 1 N/A CUM SN2018AOZ 2 WFC3/IR MULTIAC IR-UVIS F110W 1 none none none 1 N/A CUM SN2018AOZ 2 WFC3/IR MULTIAC IR-UVIS F110W 2 none none none 1 N/A CUM SN2018AOZ 2 WFC3/IR MULTIAC IR-UVIS F110W 3 none none none 1 N/A CUM 16078( 4) - 20-Mar-2020 21:54:05 - [ 6] Visit: 03 (visit3) Visit Requirements: GROUP 03, 01, 02 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 SN2018AOZ WFC3/UVI ACCUM UVIS2 F555W 1 856 S PATTERN 1 1 S (2568 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F555W 1 none none none 1 N/A S SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F555W 2 none none none 1 N/A S SN2018AOZ 1 WFC3/UVI ACCUM UVIS2 F555W 3 none none none 1 N/A S 16078( 4) - 20-Mar-2020 21:54:05 - [ 7] Summary Form for Proposal 16078 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-UVIS, UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=9, NSAMP=10, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-JUN-2020:00:00:00 AND 30-AUG-2020:00:00:00, GROUP 01, 02, 03 WITHIN 7D, GROUP 02, 01, 03 WITHIN 7D, GROUP 03, 01, 02 WITHIN 7D, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, PATTERN 2 1, PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F438W, F555W, F600LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2018AOZ ------------------------------------------------------------------------------------------------------------------------------------