13782( 2) - 14-Jul-2014 15:46:41 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13782 Version: 2 Check-in Time: 14-Jul-2014 15:46:41 STScI Edit Number: 0 Title The Double Supernova in NGC 6984 ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Dan Milisavljevic Smithsonian Institution Astrophysical Y Observatory CoI: Dr. Robert A. Fesen Dartmouth College N CoI: Dr. Raffaella Margutti Harvard University N CoI: Prof. Alicia M. Soderberg Harvard University N CoI: Dr. Emmanouil Chatzopoulos University of Chicago N CoI: Dr. John J. Eldridge The University of Auckland N CoI: Maria Drout Harvard University N CoI: Mr. Nathan Sanders Harvard University N CoI: Dr. Jerod Parrent Harvard University N CoI: Dr. Atish Kamble Harvard University N CoI: Prof. Robert P. Kirshner Harvard University N ------------------------------------------------------------------------------------ Abstract In 2012 and 2013, two Type Ib/c supernovae -- SN2012im and SN2013ek -- were discovered at virtually the same location (< 0.4 arcsec) in NGC 6984 (D ~ 65 Mpc). A double supernova of this sort has never been observed before and it is possible that the two explosions are somehow physically linked. The uniqueness of the discovery prompted HST/WFC3 images of the region to be obtained in Cycle 21 via Director's Discretionary time led by our group. Those images revealed a weak source nearby to SN2013ek that could be late-time emission from SN2012im. We propose a program of four orbits of Cycle 22 time to complete our original mission of determining the nature of this rare supernova coupling. A return visit with HST will conclusively verify whether the secondary source is indeed SN2012im. If the secondary source fades then this would mean a curious case of two neighboring but unrelated supernovae occurring within a year of each other. Alternatively, if the secondary source does not fade, then it is likely that the two events SN2012im/2013ek are connected -- a discovery that will have important ramifications in areas of high-mass binary star evolution and explosion mechanisms of core-collapse supernovae. The proposed UV and optical observations will enable us to perform a detailed investigation of the explosion site and model properties of the parent star cluster and its immediate environment. ------------------------------------------------------------------------------------ Observations Description ------------------------ These observations are designed to obtain a suite of optical and UV images of SN 2013ek and its host galaxy NGC 6984. The WFC3/UVIS will be used in a total of four orbits over two visits of Cycle 22 time. The filters F275W, F336W, F475W, F555W, F665N, and F814W will be used. The images will be dithered in a three-point sub-pixel pattern. The entire galaxy fits nicely on the UVIS2 chip. 13782( 2) - 14-Jul-2014 15:46:41 - [ 2] We have incorporated the use of post-flash to improve charge transfer efficiency. ------------------------------------------------------------------------------------ 13782( 2) - 14-Jul-2014 15:46:41 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SN2013EK EXT-STAR, SUPERNOVA RA=20H57M53.9000S, J2000 V = 26 +/- 1 DEC=-51D52'24.50" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 13782( 2) - 14-Jul-2014 15:46:41 - [ 4] 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 ------------------------------------------------------------------------------------------------------------------------------------ 13782( 2) - 14-Jul-2014 15:46:41 - [ 5] Visit: 01 Visit Requirements: BETWEEN 01-JUN-2015 AND 30-SEP-2015 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 SN2013EK WFC3/UVI ACCUM UVIS2 F555W 1 390 S PATTERN 1 1-2 S (1170 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SN2013EK WFC3/UVI ACCUM UVIS2 F814W 1 390 S S (1170 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SN2013EK WFC3/UVI ACCUM UVIS2 F336W FLASH=11 1 400 S PATTERN 1 3-4 S (1200 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 SN2013EK WFC3/UVI ACCUM UVIS2 F438W FLASH=8 1 390 S S (1170 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 SN2013EK WFC3/UVI ACCUM UVIS2 F665N FLASH=11 1 415 S POS TARG 0.5, 0.5; S (1245 S) PATTERN 1 5 ------------------------------------------------------------------------------------------------------------------------------------ 6 SN2013EK WFC3/UVI ACCUM UVIS2 F665N FLASH=11 1 415 S PATTERN 1 6 S (1245 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 SN2013EK WFC3/UVI ACCUM UVIS2 F275W FLASH=12 1 415 S PATTERN 1 7 S (1245 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 SN2013EK WFC3/UVI ACCUM UVIS2 F275W FLASH=12 1 415 S POS TARG 0.5, 0.5; S (1245 S) PATTERN 1 8 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2013EK 1 WFC3/UVI ACCUM UVIS2 F555W 1 none none none 1 N/A S SN2013EK 1 WFC3/UVI ACCUM UVIS2 F555W 2 none none none 1 N/A S SN2013EK 1 WFC3/UVI ACCUM UVIS2 F555W 3 none none none 1 N/A S SN2013EK 2 WFC3/UVI ACCUM UVIS2 F814W 1 none none none 1 N/A S SN2013EK 2 WFC3/UVI ACCUM UVIS2 F814W 2 none none none 1 N/A S SN2013EK 2 WFC3/UVI ACCUM UVIS2 F814W 3 none none none 1 N/A S 13782( 2) - 14-Jul-2014 15:46:41 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ SN2013EK 3 WFC3/UVI ACCUM UVIS2 F336W 1 none none none 2 N/A S SN2013EK 3 WFC3/UVI ACCUM UVIS2 F336W 2 none none none 2 N/A S SN2013EK 3 WFC3/UVI ACCUM UVIS2 F336W 3 none none none 2 N/A S SN2013EK 4 WFC3/UVI ACCUM UVIS2 F438W 1 none none none 2 N/A S SN2013EK 4 WFC3/UVI ACCUM UVIS2 F438W 2 none none none 2 N/A S SN2013EK 4 WFC3/UVI ACCUM UVIS2 F438W 3 none none none 2 N/A S SN2013EK 5 WFC3/UVI ACCUM UVIS2 F665N 1 none none none 3 N/A S SN2013EK 5 WFC3/UVI ACCUM UVIS2 F665N 2 none none none 3 N/A S SN2013EK 5 WFC3/UVI ACCUM UVIS2 F665N 3 none none none 3 N/A S SN2013EK 6 WFC3/UVI ACCUM UVIS2 F665N 1 none none none 3 N/A S SN2013EK 6 WFC3/UVI ACCUM UVIS2 F665N 2 none none none 3 N/A S SN2013EK 6 WFC3/UVI ACCUM UVIS2 F665N 3 none none none 3 N/A S SN2013EK 7 WFC3/UVI ACCUM UVIS2 F275W 1 none none none 4 N/A S SN2013EK 7 WFC3/UVI ACCUM UVIS2 F275W 2 none none none 4 N/A S SN2013EK 7 WFC3/UVI ACCUM UVIS2 F275W 3 none none none 4 N/A S SN2013EK 8 WFC3/UVI ACCUM UVIS2 F275W 1 none none none 4 N/A S SN2013EK 8 WFC3/UVI ACCUM UVIS2 F275W 2 none none none 4 N/A S SN2013EK 8 WFC3/UVI ACCUM UVIS2 F275W 3 none none none 4 N/A S 13782( 2) - 14-Jul-2014 15:46:41 - [ 7] Summary Form for Proposal 13782 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=11, FLASH=12, FLASH=8 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-JUN-2015 AND 30-SEP-2015, PATTERN 1 1-2, PATTERN 1 3-4, PATTERN 1 5, PATTERN 1 6, PATTERN 1 7, PATTERN 1 8, POS TARG 0.5, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F336W, F438W, F555W, F665N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names SN2013EK ------------------------------------------------------------------------------------------------------------------------------------