12370( 6) - 06-Mar-2012 21:08:54 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12370 Version: 6 Check-in Time: 06-Mar-2012 21:08:54 STScI Edit Number: 1 Title The Astrophysics of the Most Energetic Gamma-Ray Bursts ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrew S. Fruchter Space Telescope Science Institute CoI: Dr. Kuntal Misra Space Telescope Science Institute N CoI: Mr. John Graham The Johns Hopkins University N CoI: Dr. Asaf Pe'er Harvard University N CoI: Dr. Stephen T. Holland Space Telescope Science Institute N CoI: Prof. Nial R. Tanvir University of Leicester N ------------------------------------------------------------------------------------ Abstract The Large Area Telescope (LAT) of Fermi has found a sample of highly relativistic gamma-ray bursts (GRBs), which may be among the most energetic bursts ever discovered. Here we propose to use Chandra and HST to follow the late time X-ray and optical light curves of a LAT detected burst that also has excellent early multiwavelength coverage. Our observations, in conjunction with the Fermi data, will allow us to measure the energy and the bulk Lorentz factor of the explosion. Recent work on some of the most powerful GRBs begins to substantially constrain physical models of the progenitors. The energetics of the highly relativistic LAT bursts may greatly strengthen these constraints and provide new insight into the currently unknown mechanism that determines the energy in a GRB. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan three visits with HST: the first an orbit long, a second two orbits long, and a third four orbits long. The first visit will occur about around twenty days after outburst. The second will be around forty days after outburst. The exact times will be scaled according to the decay seen from the ground. The third visit will be taken at least six months after the burst to allow an accurate host subtraction. We will use the UVIS camera on WFC3 because WFC3 easily has as good sensitivity on point sources as ACS with smaller detector-induced noise sources (CTE, bias-striping, etc). We will choose the filter at the time of the ToO to match one of the best observed bands from the ground (most likely a red band). If the OT and host are sufficiently bright in the first two epochs we will divide the last epoch into 3 orbits with WFC3/UVIS and one orbit with WFC3/IR, in order to better study the environment underlying this extremely energetic burst. Real Time Justification ----------------------- Calibration Justification ------------------------- 12370( 6) - 06-Mar-2012 21:08:54 - [ 2] Additional Comments ------------------- ------------------------------------------------------------------------------------ 12370( 6) - 06-Mar-2012 21:08:54 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 GRB-110731A EXT-STAR, GAMMA RAY RA=18H42M1.0000S +/- 0.1", J2000 V = 25 BURSTER DEC=-28D32'14.90" +/- 0.1" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 12370( 6) - 06-Mar-2012 21:08:54 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type BOX WFC3-UVIS-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 4 2 Point_Spacing 0.173 0.145 Line_Spacing 0.112 Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 23.884 46.84 Angle_Between_Sides 81.785 Center_Pattern NO NO ------------------------------------------------------------------------------------------------------------------------------------ 12370( 6) - 06-Mar-2012 21:08:54 - [ 5] Visit: 02 Visit Requirements: BETWEEN 18-AUG-2011:00:00:00 AND 23-AUG-2011:00:00:00; ON HOLD On Hold Comments: This is a Target of Opportunity Visit Template Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GRB-110731A WFC3/UVI ACCUM UVIS1 F625W 1 1300 S PATTERN 1 1 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-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 1 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 2 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 3 none none none 2 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 4 none none none 2 N/A S 12370( 6) - 06-Mar-2012 21:08:54 - [ 6] Visit: 04 Visit Requirements: ORIENT 85D TO 102 D; BETWEEN 12-SEP-2011:00:00:00 AND 15-SEP-2011:00:00:00; ON HOLD On Hold Comments: This is a Target of Opportunity Visit Template Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GRB-110731A WFC3/UVI ACCUM UVIS1 F625W 1 1300 S PATTERN 1 1 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-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 1 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 2 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 3 none none none 2 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 4 none none none 2 N/A S 12370( 6) - 06-Mar-2012 21:08:54 - [ 7] Visit: 05 Visit Requirements: SAME ORIENT AS 02; BETWEEN 01-AUG-2012:00:00:00 AND 31-AUG-2012:00:00:00; ON HOLD On Hold Comments: This is a Target of Opportunity Visit Template Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 GRB-110731A WFC3/UVI ACCUM UVIS1 F625W 1 1300 S PATTERN 1 1 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-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 1 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 2 none none none 1 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 3 none none none 2 N/A S GRB-110731A 1 WFC3/UVI ACCUM UVIS1 F625W 4 none none none 2 N/A S 12370( 6) - 06-Mar-2012 21:08:54 - [ 8] Summary Form for Proposal 12370 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-AUG-2012:00:00:00 AND 31-AUG-2012:00:00:00, BETWEEN 12-SEP-2011:00:00:00 AND 15-SEP-2011:00:00:00, BETWEEN 18-AUG-2011:00:00:00 AND 23-AUG-2011:00:00:00, ON HOLD , ORIENT 85D TO 102 D, PATTERN 1 1, SAME ORIENT AS 02 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F625W ------------------------------------------------------------------------------------------------------------------------------------ Target Names GRB-110731A ------------------------------------------------------------------------------------------------------------------------------------