13360( 2) - 25-Jun-2013 20:32:02 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13360 Version: 2 Check-in Time: 25-Jun-2013 20:32:02 STScI Edit Number: 0 Title The Peculiar Type Ia Supernova 2012Z: A Massive Star Progenitor? ------------------------------------------------------------------------------------ Type Cycle GO 20 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Saurabh W. Jha Rutgers the State University of New Jersey Y CoI: Mr. Curtis McCully Rutgers the State University of New Jersey N CoI: Dr. Ryan Foley University of Illinois at Urbana - N Champaign CoI: Ms. Wen-fai Fong Harvard University N CoI: Prof. Robert P. Kirshner Harvard University N CoI: Dr. Howie Marion Harvard University N CoI: Dr. Adam Riess The Johns Hopkins University N ------------------------------------------------------------------------------------ Abstract Despite the tremendous importance of type Ia supernovae (SNe Ia), from their use as cosmological distance indicators to their contribution to the chemical enrichment of the Universe, we are still puzzled by the basic questions: what are their progenitor systems and how do they explode? Peculiar SNe Ia, objects that resemble normal SNe Ia spectroscopically, but lie off the one-parameter Phillips relationship the vast majority of SN Ia follow, play a useful role in answering these questions. By understanding what makes a small, but significant, fraction of SNe Ia different than their normal cousins, we may identify the key initial conditions and physical processes at work. Here we propose late-time HST WFC3/UVIS optical photometry of SN 2012Z, the most recent member of the peculiar SN 2002cx-like subclass of SNe Ia. We will compare our observations with extremely deep pre-explosion HST ACS images of the host galaxy NGC 1309, to test whether bright (M_I = -6) stars near the position of the SN are in fact coincident with it, testing a massive star progenitor hypothesis for this subclass of explosions, contrary to the most likely progenitor models for normal SNe Ia. We will also continue to follow the optical light curve of SN 2012Z to epochs later than any peculiar SNe Ia has been observed, in order to test signatures of explosion models for these objects. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to obtain late-time optical WFC3/UVIS VrI photometry of SN 2012Z in NGC 1309 in two epochs, once during Cycle 20 (scheduled ~500 days after maximum light), and again during Cycle 21 (sometime approximately 680 to 850 days past maximum). In the second epoch (Cycle 21) observations (between January and July 2014) we anticipate SN 2012Z will have V~26.5, r~26, and I~25.5, with an uncertainty of about 1 mag. For the comparison between models and other late-time SNe, we need S/N >~ 8 in all filters, even in a pessimistic case (with the SN 1 mag below the prediction and near the end of the observing window). We will use 3 dither positions in each filter, the best tradeoff between good PSF sampling and long 13360( 2) - 25-Jun-2013 20:32:02 - [ 2] enough exposures to produce background levels with minimal CTE losses. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 13360( 2) - 25-Jun-2013 20:32:02 - [ 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 +/- 0.1", J2000 V = 23 +/- 1 fading TYPE IA DEC=-15D23'15.60" +/- 0.1" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13360( 2) - 25-Jun-2013 20:32:02 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 13360( 2) - 25-Jun-2013 20:32:02 - [ 5] Visit: 01 Visit Requirements: SCHED 100%; BETWEEN 01-JAN-2014:00:00:01 AND 01-AUG-2014:00:00:01 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 WFC3/UVI ACCUM UVIS2 F625W 1 500 S PATTERN 2 1-3 S see below (1952 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN-2012Z WFC3/UVI ACCUM UVIS2 F555W 1 850 S S see below (3002 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN-2012Z WFC3/UVI ACCUM UVIS2 F814W 1 650 S S see below (2402 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 WFC3/UVI ACCUM UVIS2 F625W 1 none none none 1 626.0 S S SN-2012Z 1 WFC3/UVI ACCUM UVIS2 F625W 2 none none none 2 663.0 S S SN-2012Z 1 WFC3/UVI ACCUM UVIS2 F625W 3 none none none 3 663.0 S S SN-2012Z 2 WFC3/UVI ACCUM UVIS2 F555W 1 none none none 1 976.0 S S SN-2012Z 2 WFC3/UVI ACCUM UVIS2 F555W 2 none none none 2 1013.0 S S SN-2012Z 2 WFC3/UVI ACCUM UVIS2 F555W 3 none none none 3 1013.0 S S SN-2012Z 3 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 776.0 S S SN-2012Z 3 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 2 813.0 S S SN-2012Z 3 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 3 813.0 S S 13360( 2) - 25-Jun-2013 20:32:02 - [ 6] Summary Form for Proposal 13360 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-JAN-2014:00:00:01 AND 01-AUG-2014:00:00:01, PATTERN 2 1-3, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W, F625W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN-2012Z ------------------------------------------------------------------------------------------------------------------------------------