16664( 6) - 01-Dec-2022 20:30:12 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16664 Version: 6 Check-in Time: 01-Dec-2022 20:30:12 STScI Edit Number: 1 Title A repeating fast radio burst in a globular cluster at 3.6 Mpc ------------------------------------------------------------------------------------ Type Cycle GO 29 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Shriharsh Tendulkar Tata Institute of Fundamental Research, Y Bombay CoI: Dr. Jason Hessels Stichting Astronomisch Onderzoek in N Nederland (ASTRON) CoI: Dr. Cees G. Bassa Stichting Astronomisch Onderzoek in N Nederland (ASTRON) CoI: Mr. Mohit Bhardwaj Carnegie Mellon University N CoI: Dr. Franz Kirsten Chalmers University of Technology N CoI: Kenzie Nimmo Universiteit van Amsterdam N CoI: Dr. Paul Scholz University of Toronto N CoI: Prof. Kiyoshi Masui Massachusetts Institute of Technology N CoI: Prof. Emmanuel Fonseca West Virginia University Research N Corporation CoI: Dr. Shami Chatterjee Cornell University N CoI: Dr. Victoria M. Kaspi McGill University N ------------------------------------------------------------------------------------ Abstract The repeating fast radio burst (FRB) 20200120E has been localized with 100 mas precision using the European VLBI network to a globular cluster (GC) in the halo of M81, a spiral galaxy at a distance of 3.63 Mpc. The proximity of the source lends itself to detailed analysis of the FRB's environment as in the case of FRB 180916 (at a distance of 150 Mpc). GCs are known to be a hotbed of stellar interaction as proven by the presence of large populations of millisecond pulsars, low mass X-ray binaries and catacylsmic variables. However, the presence of FRB 20201020E in an low metallicity, old stellar population GC is surprising compared to the locations of most other FRBs near star forming regions and the theoretical expectations of FRBs originating from extremely active neutron stars that are typically found in such star forming regions. We request a short WFC3/UVIS observation of the GC to measure its stellar density profile, compactness, dynamic state (i.e. whether it has undergone core-collapse) and perform precise astrometry with respect to the radio reference frame to localize the FRB within the GC. ------------------------------------------------------------------------------------ Observations Description ------------------------ We propose to observe the globular cluster [PR95] 30244 in the M81 system with HST to measure its size, position, radial profile, and stellar population. This will allow us to better understand the nature of the repeating FRB 20200120E. Here we have requested observations in F438W, F606W, and F814W filters using the WFSC3/UVIS camera with a 3-point dithering for adequately sampling the PSF. ------------------------------------------------------------------------------------ 16664( 6) - 01-Dec-2022 20:30:12 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M81-GC STELLAR CLUSTER, RA=09H57M54.7030S, J2000 V = 19.76 GLOBULAR CLUSTER DEC=+68D49'0.80" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 16664( 6) - 01-Dec-2022 20:30:12 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 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 ------------------------------------------------------------------------------------------------------------------------------------ 16664( 6) - 01-Dec-2022 20:30:12 - [ 4] Visit: 01 Visit Requirements: 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 M81-GC WFC3/UVI ACCUM UVIS1 F814W 1 400 S GS ACQ SCENARIO BASE1BE; S see below PATTERN 2 1-3 (1651 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 M81-GC WFC3/UVI ACCUM UVIS1 F606W 1 400 S S see below (1651 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 M81-GC WFC3/UVI ACCUM UVIS1 F438W FLASH=9 1 400 S S see below (1810 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 | ------------------------------------------------------------------------------------------------------------------------------------ M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 497.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 497.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 2 657.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 1 497.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 1 497.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 657.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 1 none none none 1 497.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 2 none none none 2 656.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 3 none none none 2 657.0 S S 16664( 6) - 01-Dec-2022 20:30:12 - [ 5] Visit: 51 Visit Requirements: On Hold Comments: Additional Comments: Duplicate for failed visit 01. 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 M81-GC WFC3/UVI ACCUM UVIS1 F814W FLASH=5 1 400 S GS ACQ SCENARIO BASE1BE; S see below PATTERN 2 1-3 (1639 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 M81-GC WFC3/UVI ACCUM UVIS1 F606W 1 400 S S see below (1639 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 M81-GC WFC3/UVI ACCUM UVIS1 F438W FLASH=13 1 400 S S see below (1801 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 | ------------------------------------------------------------------------------------------------------------------------------------ M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 492.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 492.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 2 655.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 1 492.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 1 492.0 S S M81-GC 2 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 655.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 1 none none none 1 492.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 2 none none none 2 654.0 S S M81-GC 3 WFC3/UVI ACCUM UVIS1 F438W 3 none none none 2 655.0 S S 16664( 6) - 01-Dec-2022 20:30:12 - [ 6] Visit: 52 Visit Requirements: ORIENT 110D TO 177 D 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 M81-GC WFC3/UVI ACCUM UVIS1 F606W 1 600 S PATTERN 3 1 S see below (2708 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 | ------------------------------------------------------------------------------------------------------------------------------------ M81-GC 1 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 1 677.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 1 677.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 1 677.0 S S M81-GC 1 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 1 677.0 S S 16664( 6) - 01-Dec-2022 20:30:12 - [ 7] Summary Form for Proposal 16664 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=13, FLASH=5, FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1BE, ORIENT 110D TO 177 D, PATTERN 2 1-3, PATTERN 3 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F438W, F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M81-GC ------------------------------------------------------------------------------------------------------------------------------------