0 Assigned ID: 1272 ----- Attempting Submission 1 (Fri Sep 30 18:52:03 GMT 2016) ----- 0 ----- Attempting Submission 1 (Fri Dec 16 23:04:19 GMT 2016) ----- Solving the enigma of Fast Radio Burst 121102 FRB 121102 is the only known repeating source in the class of mysterious phenomena known as Fast Radio Bursts (FRBs). Through our very recent VLA campaign, we have a direct sub-arcsecond localization of FRB 121102, the first for any FRB. At the location of the burst, VLA and EVN observations show a potentially variable radio point source and archival Keck imaging shows a faint (R = 24.5 mag), possibly extended object. This is an unprecedented opportunity to learn about the yet unknown origins of FRBs, their distance scales, and host properties. We are requesting a two and a half orbit HST/WFC3 imaging observation that will enable us to discriminate the host type (a redshifted spiral or elliptical galaxy or an underluminous AGN) and the location of the burst within the host (nuclear or offset), with critically different implications for the underlying source class. While we are pursuing follow-up multi-wavelength imaging and ground-based spectroscopy, no other facility, ground-based or otherwise, can provide the host morphology information that we can get with HST imaging. The aim of this observation is to study the spatial structure in a dwarf galaxy hosting FRB 121102. Stellar Physics Intergalactic Medium and Cosmology 3 false false false false false false SUPPORTED GALAXY DWARF COMPACT This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 1 false POS-TARG MOSAIC DITHER 2 2.414 WFC3-UVIS-DITHER-LINE false false 0.145 2 85.759 POS-TARG WFC3-UVIS-GAP-LINE 46.84 4 true /Users/spt/Dropbox/proposals/HST/2016_Midcycle/FRB121102/Phase II/OP-cache/HST14890_phaseII_4ptIR+4ptUVIS-v01.xml The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. WFC3/IR (1 orbit) + WFC3/UVIS (2 orbits) (Tic-Visit :proposal-id 14890 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "16-Dec-2016 16:02:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 4190160 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14890 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14890 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2864 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3245 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14890 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3023 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3245 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14890 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3023 :al-overhead-at-end 122 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3245 :pcs-gap 0 ) true 3 0