Please find attached our DDT proposal "The UV behaviour of GRB 161219B/SN2016jca" -25177103 Assigned ID: 1313 ----- Attempting Submission 1 (Wed Jan 04 12:36:31 GMT 2017) ----- preliminary submission 1170521974 ----- Attempting Submission 1 (Thu Jan 12 13:18:21 GMT 2017) ----- The connection between long duration gamma-ray bursts and the stripped-envelope supernova is now secure, however, central questions remain about the nature of the supernovae and the power sources that drive them. Progress in these areas can be made through in-depth observations of nearby GRBs, in which the supernova light is sufficiently bright for detailed studies. However, such events are extremely rare, with only a handful of classical long-duration GRBs being found at z<0.2. Here we request observations of the recent GRB 161219B, and its supernova SN 2016jca. Utilising the unique ultraviolet capabilities of HST we will map the UV spectrum and its evolution with time. At a minimum, this will provide a route to tracking the afterglow and decomposing afterglow and supernova and host contributions -- diagnostics that ground-based observations alone struggle to achieve. However, our sensitive UV observations will also probe the UV properties of a GRB-SN for the first time, providing insight into the metal content of the progenitor, and crucially into the nature of the central engine, which may power the prompt emission of the burst, and continue to provide energy to event at much later times. Recent observations suggest that in extremum these engines may drive supernovae to exceptional luminosities (the so-called superluminous supernovae) and provide a link between the most powerful explosions in the Universe. Our observations may offer the route to identifying such an engine at work in a lower luminosity supernova, solidifying this link. We request G280L spectroscopy of the afterglow/supernova assocaited with GRB 161219B at z=0.15. We will obtain a 4-point dither sequence of observations, as well as a short exposure in F390W for astrometric purposes that will also provide a photometric point and a measurement of the host galaxy. To provide a means of cosmic ray rejection we will obtain two short exposures, and to avoid buffer dump issues for the short exposures have placed them immediately before and after the grism observations. Given the position angle of the host galaxy a roll angle low in the available range (15-25 degrees) is ideal. Intergalactic Medium and Cosmology 0 SUPPORTED GALAXY HIGH REDSHIFT GALAXY J2000 J2000 WFC3/UVIS Spectroscopic No No G280 WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F390W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F390W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. 1484212937278 (Tic-Visit :proposal-id 14901 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "12-Jan-2017 09:22:16.0" :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 1732496 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14901 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14901 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2660 :al-overhead-at-end 122 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2993 :pcs-gap 0 ) false 1 0 Awaiting Dark GRB position from Chandra