15089( 13) - 29-Sep-2022 19:14:16 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15089 Version: 13 Check-in Time: 29-Sep-2022 19:14:16 STScI Edit Number: 11 Title Identify the signature of neutron star mergers through rapid Hubble observations of a short GRB ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Eleonora Troja Universita di Roma Tor Vergata Y CoI: Dr. Stephen Bradley Cenko NASA Goddard Space Flight Center N CoI: Nobuyuki Kawai Tokyo Institute of Technology - TIT N CoI: Dr. Amy Lien NASA Goddard Space Flight Center N CoI: Dr. Taka Sakamoto Aoyama Gakuin University N CoI: Brendan O'Connor George Washington University N CoI: Dr. Alexander Kutyrev 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 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 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. ------------------------------------------------------------------------------------ Observations Description ------------------------ Below we provide an illustrative description of our observational strategy. Given the broad range of short GRB redshifts, afterglow and host properties, the exact details of the observations (response time, cadence, and filters) will be determined on a case by case basis. We request four epochs of observations, the exact times will be scaled according to the observed afterglow decay, the GRB distance scale, and the total time span of the ground-based data. We will plan our observations in order to require a reaction time >2 days. Each epoch will consist of three orbits in order to image the target in different colors. In case of a rare nearby z~0.1 event we may request to perform spectroscopic observations. We remark that the choice of UVIS and IR filters reported in this observing form is preliminary, and the final selection will be made at the time of the ToO in order to match the best sampled light curves from the ground. ------------------------------------------------------------------------------------ 15089( 13) - 29-Sep-2022 19:14:16 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 GRB EXT-STAR, GAMMA RAY RA=02H58M10.5800S +/- 0.5", J2000 V = 21 BURSTER DEC=-08D57'29.82" +/- 0.5" Reference Frame: Other: XRT Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 15089( 13) - 29-Sep-2022 19:14:16 - [ 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: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.572 Line_Spacing 0.365 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15089( 13) - 29-Sep-2022 19:14:16 - [ 4] Visit: 01 (V1) Visit Requirements: SCHED 100%; ORIENT 290D TO 320 D; BETWEEN 28-SEP-2019:00:00:00 AND 04-OCT-2019:00:00:00; SEQ 01, 02 WITHIN 2 Orbits 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 GRB WFC3/IR MULTIAC GRISM1024 F110W NSAMP=6, SAMP-SEQ=STEP50 1 DEF GS ACQ SCENARIO BASE1B3; CUM (147.691 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GRB WFC3/IR MULTIAC GRISM1024 G102 NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 2 CUM (2011.747 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 | ------------------------------------------------------------------------------------------------------------------------------------ GRB 1 WFC3/IR MULTIAC GRISM102 F110W 1 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F110W 2 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F110W 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 1 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 2 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 4 none none none 1 N/A CUM 4 15089( 13) - 29-Sep-2022 19:14:16 - [ 5] Visit: 02 (V2) Visit Requirements: SCHED 100%; SAME ORIENT AS 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 GRB WFC3/IR MULTIAC GRISM1024 F160W NSAMP=6, SAMP-SEQ=STEP50 1 DEF GS ACQ SCENARIO BASE1B3; CUM (147.691 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GRB WFC3/IR MULTIAC GRISM1024 G141 NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 2 CUM (2011.747 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 | ------------------------------------------------------------------------------------------------------------------------------------ GRB 1 WFC3/IR MULTIAC GRISM102 F160W 1 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F160W 2 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F160W 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 1 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 2 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 4 none none none 1 N/A CUM 4 15089( 13) - 29-Sep-2022 19:14:16 - [ 6] Visit: 03 (V3) Visit Requirements: SCHED 100%; ORIENT 290D TO 320 D; AFTER 01 BY 25 D TO 35 D; SEQ 03, 04 WITHIN 2 Orbits; ON HOLD FOR 01 On Hold Comments: Execute ~30 d after V1 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 GRB WFC3/IR MULTIAC GRISM1024 F110W NSAMP=6, SAMP-SEQ=STEP50 1 DEF GS ACQ SCENARIO BASE1B3; CUM (147.691 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GRB WFC3/IR MULTIAC GRISM1024 G102 NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 2 CUM (2011.747 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 | ------------------------------------------------------------------------------------------------------------------------------------ GRB 1 WFC3/IR MULTIAC GRISM102 F110W 1 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F110W 2 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F110W 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 1 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 2 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G102 4 none none none 1 N/A CUM 4 15089( 13) - 29-Sep-2022 19:14:16 - [ 7] Visit: 04 (V4) Visit Requirements: SCHED 100%; SAME ORIENT AS 03; AFTER 02 BY 25 D TO 35 D; ON HOLD FOR 02 On Hold Comments: Execute ~30 days after V2 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 GRB WFC3/IR MULTIAC GRISM1024 F160W NSAMP=6, SAMP-SEQ=STEP50 1 DEF GS ACQ SCENARIO BASE1B3; CUM (147.691 PATTERN 1 1 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 GRB WFC3/IR MULTIAC GRISM1024 G141 NSAMP=11, SAMP-SEQ=SPARS50 1 DEF PATTERN 2 2 CUM (2011.747 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 | ------------------------------------------------------------------------------------------------------------------------------------ GRB 1 WFC3/IR MULTIAC GRISM102 F160W 1 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F160W 2 none none none 1 N/A CUM 4 GRB 1 WFC3/IR MULTIAC GRISM102 F160W 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 1 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 2 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 3 none none none 1 N/A CUM 4 GRB 2 WFC3/IR MULTIAC GRISM102 G141 4 none none none 1 N/A CUM 4 15089( 13) - 29-Sep-2022 19:14:16 - [ 8] Summary Form for Proposal 15089 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures GRISM1024 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=11, NSAMP=6, SAMP-SEQ=SPARS50, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 25 D TO 35 D, AFTER 02 BY 25 D TO 35 D, BETWEEN 28-SEP-2019:00:00:00 AND 04-OCT-2019:00:00:00, GS ACQ SCENARIO BASE1B3, ON HOLD FOR 01, ON HOLD FOR 02, ORIENT 290D TO 320 D, PATTERN 1 1, PATTERN 2 2, SAME ORIENT AS 01, SAME ORIENT AS 03, SCHED 100%, SEQ 01, 02 WITHIN 2 Orbits, SEQ 03, 04 WITHIN 2 Orbits ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F110W, F160W, G102, G141 ------------------------------------------------------------------------------------------------------------------------------------ Target Names GRB ------------------------------------------------------------------------------------------------------------------------------------