POS TARG & PATTERN should be used carefully with ACS ramp or WFC3 quad filters as central wavelengths & transmission efficiencies vary within the apertures. 0 ----- Attempting Submission 1 (Thu Jul 24 11:47:36 GMT 2014) ----- Small offset pattern is used to improve sampling, we foresee no issues with filter transmission variations over this small scale Explosive detonations on the surfaces of accreting white dwarfs play a key role in establishing viable progenitor pathways towards Type Ia supernova explosions. If the white dwarf is accreting hydrogen deficient material, helium shell-flash driven eruptions can occur on its surface. Thus far only one such helium nova event has been observed in Nova Puppis 2000 = V445 Pup. We have discovered an expanding bipolar shell involving fast moving ejecta of He-rich material surrounding this binary. This used state of art ground-based AO imaging and IFU spectroscopy. However, we have now reached the limit of what can be done from the ground and therefore request high spatial resolution HST imaging of the ejecta in V445 Pup. These Cycle 22 observations are the 2nd epoch of our HST campaign, to be compared with the existing Cycle 20 data. These narrow band images will allow us to map the expanding ejecta in the [OII], [OIII] and HeI lines, to be directly compared with kinematical measurements based on the same lines. This will allow us to determine a robust distance using the expansion parallax method and study the ionisation structure of the shells and knots we have seen in our broadband AO images. Splitting the observations over two cycles is necessary in order to provide sufficient baseline to accurately measure the on-sky expansion which is estimated to proceed at an angular speed of 0.3"/year. Our imaging targets an extended source resolving the ejecta of a nova eruption in 2000 using WPFC3/UVIS. The filters are chosen to target previously detected emission lines covering [OIII] with F502N, [OII] with FQ727N and HeI with F680N. We have supporting ground-based data that map the kinematics of these lines using IFU spectroscopy while the target position is accurately known from recent ground-based imaging. All our exposures use the same 3-point dither pattern to improve sampling and permit cosmic ray rejection. Exposure times are scaled to reflect the observed relative line strengths while at the same time pack the 2-orbit long visit efficiently. Thus F680N receives the longests exposure time and takes up the whole of orbit 1, followed by F502N and some short FQ727N exposures in orbit 2. We have chosen the optimal UVIS aperture for our F502N and F680N exposures, while the FQ727N exposures will use the quadrant D sub-array only in sync with the filter and to save some overheads. We have decided to enable the post-FLASH as an extra option, since we believe our relatively short exposure times with narrow-band filters will benefit from this procedure. We verified background levels using the ETC and request a post-flash level of 15e for the F502N and FQ727 exposures as these have the lowest background per exposure (<5e), while 10e is sufficient for the F680N exposure (with ~5e). -------- Realtime Justification -------- N/A ------ Calibration Justification ------- N/A --------- Additional Comments ---------- This set of images is a repeat of the sequence of filters observed in Cycle 20 HOT STARS 12 false false 0.0 0.0 false false false SUPPORTED STAR CLASSICAL NOVA EMISSION LINE NEBULA Position determined from recent good seeing CCD imaging at the Magellan telescope with a WCS referenced to ICRS. Note that target is currently significantly fainter than on DSS plates as the nova eruption casued extensive local extinction. J2000 J2000 J=17.36 +/- 0.07 WFC3/UVIS Imaging No No F502N WFC3/UVIS Imaging No No F680N WFC3/UVIS Imaging No No FQ727N WFC3/UVIS Imaging No No F502N WFC3/UVIS Imaging No No F680N WFC3/UVIS Imaging No No FQ727N POS-TARG DITHER 0.135 Standard 3-pt line dither with centering enabled LINE false true 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 2 false 1406108834650 /tmp/OPVisit4147635160743810370.xml The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. Cycle 22 epoch, to be matched with Cycle 20 imaging (Tic-Visit :proposal-id 13685 :visit-id "01" :proposal-version -1 :trans-version "20140605" :date "23-Jul-2014 10:47:14.0" :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 1943648 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13685 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13685 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2907 :al-overhead-at-end 119 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3241 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13685 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3019 :al-overhead-at-end 168 :internal-dur-at-end 583 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3241 :pcs-gap 0 ) true 2 0 F680N over 3pt dither post-FLASH of 10e to reflect low expected background F502N over 3pt dither post-FLASH of 15e to reflect low expected background FW727 over 3pt dither, quadrant D sub-array post-FLASH of 15e to reflect low expected background