0 ----- Attempting Submission 2 (Wed Dec 02 14:09:14 GMT 2015) ----- HST Phase II Proposal 13941 (go13941_phase2.apt) successfully submitted. Receipt: # 13941-2 ----- Attempting Submission 3 (Thu Dec 03 12:49:09 GMT 2015) ----- 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 a 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 (few days) 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. We request two orbits with the WFC3/UVIS F606W filter and WFC/IR 106W filter. Filters were chosen to match an earlier observation of the same target. 12 false false false false SUPPORTED STAR GAMMA RAY BURSTER JET SUPERNOVA X-RAY TRANSIENT NO J2000 POS-TARG DITHER 0.605 LINE false false 3 41.788 WFC3-IR-DITHER-LINE-3PT 1 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 6 false 1449166819049 /private/var/folders/bl/s7q0tqnn5gbcbyvcfnrhj2rh0004nc/T/OPVisit5797987135710083846.xml The scheduling data was generated by CASM 23.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13941 :visit-id "01" :proposal-version -1 :trans-version "20150609" :date "03-Dec-2015 13:20:18.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1938384 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13941 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13941 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2563 :al-overhead-at-end 0 :internal-dur-at-end 65 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13941 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2912 :al-overhead-at-end 116 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3218 :pcs-gap 0 ) false 2 0