0 ----- Attempting Submission 1 (Thu Jul 20 14:52:30 GMT 2017) ----- ----- Attempting Submission 2 (Mon Sep 09 15:57:33 GMT 2019) ----- HST Phase II Proposal 15089 (new15089.apt) successfully submitted. Receipt: # 15089-2 ----- Attempting Submission 3 (Mon Sep 09 15:58:00 GMT 2019) ----- HST Phase II Proposal 15089 (new15089.apt) successfully submitted. Receipt: # 15089-3 ----- Attempting Submission 4 (Tue Sep 10 08:21:01 GMT 2019) ----- Identify the signature of neutron star mergers through rapid Hubble observations of a short GRB 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. 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. Cosmology 3 false false false false false false false SUPPORTED EXT-STAR GAMMA RAY BURSTER NO J2000 WFC3/UVIS Imaging No No F606W WFC3/IR Imaging No No F110W WFC3/IR Imaging No No F160W POS-TARG DITHER 0.605 LINE false false 3 41.788 WFC3-IR-DITHER-LINE-3PT 1 false POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 2 false Timing link suitability includes constraints ([Sequence (01 02) within 0.1 days] [03 After 01 by 28.0 to 35.0 days]) The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. 1569639415000 296.24869 (Tic-Visit :proposal-id 15089 :visit-id "01" :proposal-version -1 :trans-version "20190514" :date "10-Sep-2019 10:13:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1201200 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15089 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15089 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2573 :al-overhead-at-end 0 :internal-dur-at-end 500 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2922 :pcs-gap 0 ) false 1 0 Timing link suitability includes constraints ([Sequence (01 02) within 0.1 days] [04 After 02 by 28.0 to 35.0 days]) The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. 1569645802000 296.24869 (Tic-Visit :proposal-id 15089 :visit-id "02" :proposal-version -1 :trans-version "20190514" :date "10-Sep-2019 09:56:43.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1201200 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15089 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15089 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2573 :al-overhead-at-end 0 :internal-dur-at-end 500 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2922 :pcs-gap 0 ) false 1 0 Timing link suitability includes constraints ([Sequence (03 04) within 0.1 days] [03 After 01 by 28.0 to 35.0 days]) The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. 1572104049000 300.4633376106676 (Tic-Visit :proposal-id 15089 :visit-id "03" :proposal-version -1 :trans-version "20190514" :date "10-Sep-2019 10:14:26.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1201200 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15089 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15089 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2573 :al-overhead-at-end 0 :internal-dur-at-end 500 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2922 :pcs-gap 0 ) false 1 0 Execute ~30 d after V1 Timing link suitability includes constraints ([Sequence (03 04) within 0.1 days] [04 After 02 by 28.0 to 35.0 days]) The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. 1572109769000 300.4633376106676 (Tic-Visit :proposal-id 15089 :visit-id "04" :proposal-version -1 :trans-version "20190514" :date "10-Sep-2019 09:57:46.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1201200 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15089 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15089 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2573 :al-overhead-at-end 0 :internal-dur-at-end 500 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2922 :pcs-gap 0 ) false 1 0 Execute ~30 days after V2