13799( 7) - 29-Dec-2014 16:37:10 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13799 Version: 7 Check-in Time: 29-Dec-2014 16:37:10 STScI Edit Number: 2 Title Constraining Type Ia Supernova Nucleosynthesis and Explosion Models Using Late-Time Photometry of SN2012cg ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Or Graur New York University Y CoI: Dr. Michael Shara American Museum of Natural History N CoI: Dr. David R. Zurek American Museum of Natural History N ------------------------------------------------------------------------------------ Abstract We propose to use WFC3 photometry from the near UV to the near IR to sample the bolometric light curve of the nearby Type Ia supernova (SN Ia) SN2012cg at late times (>900 days after maximum light). This light curve will allow us to conduct a fundamental test of the theoretically predicted behavior of SN Ia light curves at late times. We will observationally determine, for the first time, whether the nuclear physics of SN Ia ejecta is solely determined by the radioactive decay of 56Co to 56Fe, or whether (and by how much) other nuclear heating mechanisms (such as the leptonic decays of 57Co and 55Fe) become discernible, as predicted. ------------------------------------------------------------------------------------ Observations Description ------------------------ Due to the high background of the galaxy at the location of the supernova, we will split our orbits between two epochs, the first when the supernova is ~925 days after maximum light, during December 13-19 2014, and the second when it is ~975 days after maximum light, during February 4-7 2015. In each epoch, both orbits will use the WFC3/UVIS F350LP filter, which covers the main UV-optical range of 300-1000 nm in which SNe Ia are usually observed. In each orbit, we will perform three exposures using the default WFC3-UVIS-LINE-3PT dither. To maximize the UVIS orbits, we will use the 1024x1024 UVIS subarray, centered on the location of the supernova. Based on similar images of the supernova in F350LP taken by GO-12880 (PI: A. Riess) and extrapolating the decaying light curve of the supernova out to our epochs, we expect the supernova to be at least as bright as 26-26.5 mag in F350LP. Furthermore, we have determined that two orbits per visit in F350LP are sufficient to obtain a signal-to-noise ratio ~20 in this filter, at our chosen epochs, which is high enough to distinguish between the various predictions tested here. UPDATE: Following our first epoch of observations, we have determined that our images are limited by the noise from the galaxy background. Thus, we cannot improve the signal-to-noise ratio of our target by observing it for more than one orbit. It is better, then, to split our remaining two orbits into two separate epochs. ------------------------------------------------------------------------------------ 13799( 7) - 29-Dec-2014 16:37:10 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2012CG EXT-STAR, SUPERNOVA RA=12H27M12.8300S, J2000 V = 24.0 +/- 0.3 TYPE IA DEC=+09D25'13.10" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13799( 7) - 29-Dec-2014 16:37:10 - [ 3] 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 ------------------------------------------------------------------------------------------------------------------------------------ 13799( 7) - 29-Dec-2014 16:37:10 - [ 4] Visit: 01 Visit Requirements: BETWEEN 13-DEC-2014:00:00:00 AND 19-DEC-2014:00:00:00 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 SN2012CG WFC3/UVI ACCUM UVIS2-M1K F350LP FLASH=12 1 896 S GS ACQ SCENARIO BASE1B3; S 1C-SUB (2688 S) PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2012CG WFC3/UVI ACCUM UVIS2-M1K F350LP FLASH=12 1 933 S PATTERN 2 2 S 1C-SUB (2799 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 1 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 2 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 3 none none none 1 N/A S K1C-SUB SN2012CG 2 WFC3/UVI ACCUM UVIS2-M1 F350LP 1 none none none 2 N/A S K1C-SUB SN2012CG 2 WFC3/UVI ACCUM UVIS2-M1 F350LP 2 none none none 2 N/A S K1C-SUB SN2012CG 2 WFC3/UVI ACCUM UVIS2-M1 F350LP 3 none none none 2 N/A S K1C-SUB 13799( 7) - 29-Dec-2014 16:37:10 - [ 5] Visit: 02 Visit Requirements: BETWEEN 04-FEB-2015:00:00:00 AND 07-FEB-2015:00:00:00 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 SN2012CG WFC3/UVI ACCUM UVIS2-M1K F350LP FLASH=12 1 896 S GS ACQ SCENARIO BASE1B3; S 1C-SUB (2688 S) PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 1 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 2 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 3 none none none 1 N/A S K1C-SUB 13799( 7) - 29-Dec-2014 16:37:10 - [ 6] Visit: 03 Visit Requirements: BETWEEN 26-APR-2015:00:00:00 AND 29-APR-2015:00:00:00 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 SN2012CG WFC3/UVI ACCUM UVIS2-M1K F350LP FLASH=12 1 896 S GS ACQ SCENARIO BASE1B3; S 1C-SUB (2688 S) PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 1 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 2 none none none 1 N/A S K1C-SUB SN2012CG 1 WFC3/UVI ACCUM UVIS2-M1 F350LP 3 none none none 1 N/A S K1C-SUB 13799( 7) - 29-Dec-2014 16:37:10 - [ 7] Summary Form for Proposal 13799 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2-M1K1C-SUB ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=12 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 04-FEB-2015:00:00:00 AND 07-FEB-2015:00:00:00, BETWEEN 13-DEC-2014:00:00:00 AND 19-DEC-2014:00:00:00, BETWEEN 26-APR-2015:00:00:00 AND 29-APR-2015:00:00:00, GS ACQ SCENARIO BASE1B3, PATTERN 2 1, PATTERN 2 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F350LP ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2012CG ------------------------------------------------------------------------------------------------------------------------------------