13941( 9) - 03-Dec-2015 18:32:12 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13941 Version: 9 Check-in Time: 03-Dec-2015 18:32:12 STScI Edit Number: 6 Title IDENTIFY THE SIGNATURE OF NEUTRON STAR MERGERS THROUGH RAPID CHANDRA/HUBBLE OBSERVATIONS OF A SHORT GRB ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Eleonora Troja University of Maryland Y ------------------------------------------------------------------------------------ Abstract The afterglow of some short GRBs displays a late-time rebrightening, visible a few days after the gamma-ray burst. Recent HST observations provided tantalizing evidence that such a late-time bump could be explained as the emergence of the underlying kilonova emission. This would represent the incontrovertible signature of a neutron star merger, and the first direct link between short GRBs and their progenitors. Here we ask for a rapid (few days) and deep Chandra/HST follow-up observation of a short duration GRB in order to detect the expected kilonova bump, and to constrain the origin of the observed emission. Multi-band observations, and in particular X-rays, are critical to pin down the nature of the observed rebrightening, and to distinguish it from the standard afterglow emission. ------------------------------------------------------------------------------------ Observations Description ------------------------ We request two orbits with the WFC3/UVIS F606W filter and WFC/IR 106W filter. Filters were chosen to match an earlier observation of the same target. ------------------------------------------------------------------------------------ 13941( 9) - 03-Dec-2015 18:32:12 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GRBTARGET STAR, GAMMA RAY RA=12H32M4.9850S +/- 0.5", J2000 V = 30 BURSTER, JET, DEC=-10D56'0.21" +/- 0.5" SUPERNOVA, X-RAY TRANSIENT Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 13941( 9) - 03-Dec-2015 18:32:12 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 6 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13941( 9) - 03-Dec-2015 18:32:12 - [ 4] Visit: 01 Visit Requirements: BEFORE 31-DEC-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 GRBTARGET WFC3/IR MULTIAC IR F160W NSAMP=14, SAMP-SEQ=STEP100 1 DEF GS ACQ SCENARIO BASE1B3; CUM (2397.699 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GRBTARGET WFC3/UVI ACCUM UVIS F606W 1 400 S PATTERN 6 2 S see below (2520 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 | ------------------------------------------------------------------------------------------------------------------------------------ GRBTARGET 1 WFC3/IR MULTIAC IR F160W 1 none none none 1 N/A CUM GRBTARGET 1 WFC3/IR MULTIAC IR F160W 2 none none none 1 N/A CUM GRBTARGET 1 WFC3/IR MULTIAC IR F160W 3 none none none 1 N/A CUM GRBTARGET 2 WFC3/UVI ACCUM UVIS F606W 1 none none none 2 630.0 S S GRBTARGET 2 WFC3/UVI ACCUM UVIS F606W 2 none none none 2 630.0 S S GRBTARGET 2 WFC3/UVI ACCUM UVIS F606W 3 none none none 2 630.0 S S GRBTARGET 2 WFC3/UVI ACCUM UVIS F606W 4 none none none 2 630.0 S S 13941( 9) - 03-Dec-2015 18:32:12 - [ 5] Summary Form for Proposal 13941 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR, UVIS ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=14, SAMP-SEQ=STEP100 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 31-DEC-2015:00:00:00, GS ACQ SCENARIO BASE1B3, PATTERN 1 1, PATTERN 6 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W, F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GRBTARGET ------------------------------------------------------------------------------------------------------------------------------------