0 Assigned ID: 614 ----- Attempting Submission 1 (Fri Apr 08 17:27:31 GMT 2016) ----- HST Phase I Proposal 614 (Ou4_Cycle24.apt) successfully submitted. Receipt: # 614-1 Following mail exchanges with Sylvia Baggett about contamination by scattered light, I have revised the orientation ranges (61-79 degrees instead of 92-110 degrees) to keep a V=10.7-mag star on the quadrant B of UVIS1. -1999667900 ----- Attempting Submission 1 (Tue Jul 12 11:33:55 GMT 2016) ----- ----- Attempting Submission 2 (Wed Sep 07 16:28:20 GMT 2016) ----- Ou4 is a giant bipolar outflow with a total length of 1.2 degrees on the sky that was discovered in the optical in the direction of the blister HII region Sh2-129. The distance, the nature, and the driving source of Ou4 are, however, not known. Ou4 is relevant for the study of the eruptive phenomena producing collimated outflows from evolved low-mass binary stars and young, massive stellar systems. Our morpho-kinematics study of the Ou4 south bow-shock has allowed us to predict its expansion proper motion that is directly related to its distance. We propose to image the brightest [O III] emission of this bow-shock with the UVIS channel of the WFC3 in Cycle 24 and 26 in order to determine the distance of this largest known stellar bipolar outflow from its expansion proper motions. This measurement is crucial to determine the true nature of Ou4: either a foreground planetary nebula or a giant bipolar outflow launched ~90,000 years ago by HR 8119, the young massive triple system ionising Sh2-129. We use the WFC3/UVIS channel with the F502N narrow filter to survey the brightest emission of the 5007 A line of the [O III] doublet in the Ou4 giant bipolar outflow. We execute dithered exposures using the B6 pattern (pre-defined WFC3-UVIS-MOS-DITH-LINE pattern has been modified), which combines two step over the chip gap to maximize the surveyed area and sub-pixel steps to improve the PSF sampling (WFC3 ISR 2010-09). The six frames are executed inside the same orbit for the best dither pointing accuracy. We use parallel buffer dumps. We add a flash at the end of each exposure (12 electrons) to reduce the charge losses during the detector readouts. Stellar Physics 12 false false false false false false SUPPORTED ISM BIPOLAR OUTFLOW EMISSION LINE NEBULA HII REGION SHOCK FRONT WIND YES The target is extended and has a very small expansion proper motion. The pointing coordinates are optimized to maximize the emission survey. The flux is our surface brightness threshold in erg/s/cm2/arcsec2. J2000 J2000 2.25E-16 WFC3/UVIS Imaging No No F502N POS-TARG DITHER DITHER 2 2.632 Pre-defined WFC3-UVIS-MOS-DITH-LINE pattern has been modified to obtain B6 pattern (WFC3 ISR 2010-09). WFC3-UVIS-MOS-DITH-LINE false true 0.119 3 47.134 POS-TARG WFC3-UVIS-MOS-DITH-LINE 33.715 1 true /home/grosso/HST/Cycle_24/Ou4/Phase_II/OP-cache/Ou4_Cycle24_phase_II_revised-v01.xml 1473265059179 The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. Two consecutive orbits. We require a specific orientation to maximize the survey of this bow shock and to exclude a V=10.7-mag star from the detector in order to prevent any filter and window ghost artifacts (the latter being produced in a such narrow filter image by star with V<12 mag in quadrant D; WFC3 ISR 2011-16) that would disturb our proper motion measurement. We use an angle tolerance of 9 degrees to increase the schedulability (22 Oct.-9 Nov. 2016 and 11 Nov.-18 Nov. 2016). (Tic-Visit :proposal-id 14780 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "07-Sep-2016 18:17:38.0" :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 3465008 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14780 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14780 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3123 :al-overhead-at-end 123 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3456 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14780 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3234 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3456 :pcs-gap 0 ) true 2 0 We add a flash at the end of each exposure (12 electrons) to reduce the charge losses during the detector readouts. We add a flash at the end of each exposure (12 electrons) to reduce the charge losses during the detector readouts.