This pattern is not used in this proposal. FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH warning fixed -1120025184 ----- Attempting Submission 1 (Tue Oct 11 20:36:24 GMT 2016) ----- ----- Attempting Submission 2 (Sat Aug 19 16:24:28 GMT 2017) ----- HST Phase II Proposal 14850 (14850.apt.xml) successfully submitted. Receipt: # 14850-2 ----- Attempting Submission 3 (Sat Aug 19 16:58:20 GMT 2017) ----- HST Phase II Proposal 14850 (14850.apt.xml) successfully submitted. Receipt: # 14850-3 ----- Attempting Submission 4 (Sat Aug 19 21:28:22 GMT 2017) ----- HST Phase II Proposal 14850 (14850.apt.xml) successfully submitted. Receipt: # 14850-4 ----- Attempting Submission 5 (Sat Aug 19 21:50:16 GMT 2017) ----- ----- Attempting Submission 6 (Wed Aug 23 13:41:51 GMT 2017) ----- ----- Attempting Submission 7 (Wed Aug 23 14:37:16 GMT 2017) ----- Warning refer to VISIT01 already scheduled Identify the signature of neutron star mergers through rapid Chandra/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 and deep Chandra/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. Multi-band observations, and in particular X-rays, are critical to pin down the nature of the observed rebrightening, and to distinguish it from the standard afterglow 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 three 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 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 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 2 false POS-TARG DITHER 0.636 LINE false false 2 41.788 WFC3-IR-DITHER-LINE 3 false The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. 1503668476000 124.03876624409298 (Tic-Visit :proposal-id 14850 :visit-id "01" :proposal-version -1 :trans-version "20170613" :date "19-Aug-2017 23:09:39.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 213904 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14850 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14850 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2645 :al-overhead-at-end 76 :internal-dur-at-end 270 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2989 :pcs-gap 0 ) true 1 0 ToO Activation The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14850 :visit-id "02" :proposal-version -1 :trans-version "20170613" :date "19-Aug-2017 23:47:28.0" :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 974896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14850 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14850 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2640 :al-overhead-at-end 0 :internal-dur-at-end 481 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2989 :pcs-gap 0 ) true 1 0 ToO Activation The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 14850 :visit-id "03" :proposal-version -1 :trans-version "20170613" :date "19-Aug-2017 23:47:29.0" :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 974896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14850 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14850 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2582 :al-overhead-at-end 0 :internal-dur-at-end 481 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2989 :pcs-gap 0 ) true 1 0 ToO Activation The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. /private/var/folders/v9/35fyv8k52f359xb15y6gdyfw0000gn/T/OPVisit7922197104964933579.xml (Tic-Visit :proposal-id 14850 :visit-id "04" :proposal-version -1 :trans-version "20170613" :date "23-Aug-2017 16:36:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 213904 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14850 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14850 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2653 :al-overhead-at-end 84 :internal-dur-at-end 270 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2989 :pcs-gap 0 ) true 1 0 ToO Activation